Love systemd timers

https://blog.tjll.net/you-dont-love-systemd-timers-enough/

by yacin • 2 months ago

396 300 2 months ago

blog.tjll.net

jjgreen5• 2 months ago

I've been almost convinced by systemd (and have switched to using it), but God the syntax of those service files is so ugly ...

WesolyKubeczek4• 2 months ago

Could have been worse.

Could have been YAML.

Could have been XML.

silvestrov2• 2 months ago

XML would have the advantage of having a grammar so we could validate the config files.

It would also make it much simpler to make good GUI editors for the files instead of the Notepad approach most unix config files take.

jjgreen5• 2 months ago

To be honest, I think either of those would have been better ...

wpm• 2 months ago

Could have been better.

Could have been XML Property Lists.

ducks

Tsiklon2• 2 months ago

XML - I see you’ve used macOS’ LaunchD, the system that inspired Systemd

whateveracct• 2 months ago

This is why I like NixOS. Defining systemd services in it is very neat.

zamadatix• 2 months ago

Never thought I'd see hackers saying INI format looked ugly of all things. It's basic, sure, but that's a good thing for something meant to be easily editable by hand from any editor. Otherwise, it's just key value pairs in named sections, how ugly can it be about that?

jjgreen5• 2 months ago

key-value pairs where the = cannot be surrounded by spaces, so I have to write

  [Service]
  Type=oneshot
  WorkingDirectory={{ home }}/current/
  Environment=RAILS_ENV=production
  ExecStart=/bin/sh -lc "bin/db-backup --verbose"

which fills me with sadness

ramon156• 2 months ago

TOML would look a lot more quiet, but I'm not sure if TOML would be a good fit

mrweasel• 2 months ago

There's definitely some weirdness to certain parts of systemd service files, but was a huge improvement over Upstart and the old SysV-style init scripts.

Over all I think Systemd get way to much criticism. You don't have to use all the parts, but if you care to go through the documentation you'll find interesting features such as journald log-shipping and systemd-machined which can manage containers and VMs.

okanat2• 2 months ago

I love how easy it is to create a completely isolated daemons with systemd. In a single .service file one can define a daemon that has a very limited view to the filesystem, can only open specific devices, uses randomized UIDs, and has limited capabilities: https://www.freedesktop.org/software/systemd/man/latest/syst...

It is way simpler and cleaner than Docker/Podman IMHO.

SEJeff• 2 months ago

Oh yes, because the well documented clean syntax of sys v init shell scripts was so nice.

If I never recall hacking in ulimit calls in the top of buggy shell scripts for crappy old services that done respect pam_limits it won’t be soon enough.

linsomniac• 2 months ago

Hard disagree. Compared to an init script, with all its boilerplate, I'd take a systemd unit file.

egorfine15• 2 months ago

As a passionate systemd hater I would say I do not agree. Cron syntax is worse.

dominiwe• 2 months ago

Relevant, a golfed systemd polyglot file that is simultaneously an executable script: https://domi.work/blog/posts/compose_polyglot/

Yes, I have too much time sometimes... and I agree, I don't like the syntax.

iso1631• 2 months ago

humble systemd

pwdisswordfishq2• 2 months ago

That the same cannot be said of its maintainer is another matter.

the_real_cher3• 2 months ago

The main person in charge of Linux itself isn't considered the most humble but they make amazing products.

hombre_fatal• 2 months ago

NixOS comes with systemd, so I've been using it as a first-class part of managing stuff. It's great, especially coming from macOS' launchd.

Which makes it nice to distribute a tool for NixOS so that it can lean into systemd instead of as some bolted-on afterthought.

Makes me wonder what you'd do if you were distributing a lifecycle-heavy tool for Linux users in general since systemd isn't ubiquitous.

I use a systemd timer to run a monthly scrub for my btrfs pool. Kinda cool how you can do increasingly useful things like skip the next scheduled event if the user initiates a scrub, do or don't accumulate tasks if you have a monthly task but the machine was offline for 6 months -- or fold them into a single task, etc.

drunner• 2 months ago

Have you been defining them directly in your flake.nix file? I too am on nixos but I keep all my configurations in their native format and symlink them with nix, that way I can take and reuse that config on a non nixos system easily.

The problem I have found is that nixos doesn't seem to pickup and run systemd timers and services placed into the ~/.config/systems/user folder and additionally things like WantedBy=default.target have no effect.

So after I restart all my services manually on reboot I agree, systems timers are cool.

Cyph0n6• 2 months ago

I define all units in Nix because:

a) It is way nicer and you get decent validation at build time

b) A LLM can port units over if the need arises; it’s a very light abstraction around systemd syntax

c) I personally don’t see how I would ever move to another distro :)

Cyph0n6• 2 months ago

+1, NixOS makes working with systemd a breeze. Defining units in Nix beats wrangling INI files.

  systemd.services.sync-recyclarr = {
    serviceConfig.Type = "oneshot";
    path = [ pkgs.podman ];
    script = ''
      podman exec -it recyclarr recyclarr sync radarr
      podman exec -it recyclarr recyclarr sync sonarr
    '';
  };
  systemd.timers.sync-recyclarr = {
    timerConfig = {
      OnCalendar = "daily";
      Persistent = true;
      Unit = "sync-recyclarr.service";
    };
    partOf = [ "sync-recyclarr.service" ];
    requires = [ "podman-recyclarr.service" ];
    wantedBy = [ "timers.target" ];
  };

Eduard4• 2 months ago

is this irony?

zamalek• 2 months ago

I don't currently have a personal use-case for container services, but Quadlets are another example of systemd (and podman) beauty. It looks like someone has gone through the trouble of making the OS+home-manager modules: https://github.com/SEIAROTg/quadlet-nix

ktm5j• 2 months ago

Oh I love them quite a lot! I use them to run all of our backup jobs, easy to set up and have never had an issue.

andrewstuart• 2 months ago

Even better is systemd socket activation.

interf4ce• 2 months ago

This is very interesting. I'm not sure what I'd use it for yet, but I imagine it could be useful for triggering ad hoc jobs over the network. Maybe have Home Assistant make a network call to kick off a daily back up when I leave the office at the end of a work day.

kevinmgranger2• 2 months ago

I believe its original motivation was just speeding up boot times by starting fewer services, even if you'd eventually want the service running. This was achieved in the past with xinetd, but systemd made the approach more popular for the masses.

urineaut• 2 months ago

A pretty nice use case I have for socket activation is for isolating containers or applications from the host network. The great thing about socket activation is that opened sockets carry over even if the application/container unshares into a different network namespace! It also works great with Podman pods with networking in the pod completely disabled and, as those are host sockets, does fully retain the connection info of peers (so logs are not just uselessly containing the gateway IP, depending on the container network config)

wmanley• 2 months ago

I design all my services expecting to receive sockets this way. It makes sandboxing easy as the service itself doesn't need network access to have a listening socket.

It's a shame docker never supported it. I feel like if they had got on board all those years ago there would be broad support across the software ecosystem for it and we wouldn't need half of these complicated iptables rules and proxies and service mesh. It would be a step towards a capability based system.

gchamonlive11• 2 months ago

Moved from cronie to systemd timers because they are resilient to system startup times. My backup strategy is to create a borg archive entry every day at a fixed time. With cronie the system needs to be running at the scheduled time, but systemd timer tolerates this and runs the service as soons as the system is available.

Btw this is my repo for the backup automation: https://github.com/gchamon/borg-automated-backups

mid-kid• 2 months ago

Cronie has a mechanism for this, called "anacron", which is called hourly by cron (on my system, /etc/cron.hourly/0anacron), and performs all the /etc/cron.{daily,weekly,monthly} tasks, no matter if the earliest possible schedule was missed (and with a configurable random delay). You can modify /etc/anacrontab to create custom schedules.

To do this at the user level, you can add something like "@hourly anacron -t /path/to/anacrontab -S /path/to/spooldir" to the user's crontab, though I've never tried this.

Many cron implementations have a similar mechanism.

gchamonlive11• 2 months ago

EDITED

This isn't the same as with systemd timer because timer lets you specify when you want to run your service exactly and will fallback to running when the system comes online. With @hourly I lose this control and multiple machines could potentially trigger backups at the same time, hogging the physical hard drives and the network.

newsoftheday2• 2 months ago

I'm sorry, I tried Googling the word "tolates" but I can't find any definition that makes sense?

runs the service as soons as the system is available.

cron has the @reboot option which I use for a few scripts and works great.

regularfry• 2 months ago

"tolerates".

gchamonlive11• 2 months ago

Typo, I meant tolerates. Fixed it.

Not an option either, because if I reboot two machines and the backup starts in both of them it'll cripple my NAS

michaelcampbell• 2 months ago

With cronie the system needs to be running at the scheduled time, but systemd timer tolerates this and runs the service as soons as the system is available.

Cronie doesn't have a `@reboot` meta-trigger?

gchamonlive11• 2 months ago

https://news.ycombinator.com/item?id=48371021

WhyNotHugo• 2 months ago

Snooze offers similar resilience to the system being offline: https://github.com/leahneukirchen/snooze

I find it very easy to reason about: a single process maps to a single recurring task.

It can track last execution into a file, yielding durable schedules when the host is offline.

stryan3• 2 months ago

Timers can work with arbitrary units (not just a similarly-named service unit) so they can be surprisingly flexible. I have a timer on my servers that starts a backup.target that fires off a full "restic backup","restic prune", "restic forget" backup cycle each morning with randomized start times and notifications. The actual restic-* units are Podman Quadlets so the whole setup runs agnosticaly of what's on the server, just as long as it has Podman and Systemd installed.

I will admit thought, timers are up there in terms of being the clunkiest systemd unit type to use on a regular basis. I get why they're split up into two files and require different start vs enable syntax's, but man sometimes I just want to create a file that runs a script and be done with it.

esperent• 2 months ago

Why do you randomize your backup times?

stryan3• 2 months ago

Should have been more clear: I use RandomizedOffsetSec= to add a random offset to a set start time (usually 4am), to prevent overloading the backup server, not truly random start times.

9dev• 2 months ago

I feel like systemd units could need a layer of abstraction above them, so instead of editing the files manually, a tool would do it, some kind of declarative CLI or something. Probably not really a concern in the age of LLMs anymore, but it feels just slightly too tedious every time.

sureglymop3• 2 months ago

I do similar stuff for backups. What's bitten me sometimes was that I disabled the timers in order to do other stuff on the restic repo (e.g. cleaning locks) but didn't see that the triggered units were still running.

stryan3• 2 months ago

Yeah I run my steps as one-shot commands to try to avoid that, but the timer/service split can be very annoying like that.

lanycrost2• 2 months ago

systemd is complex on first view, but after using it you didn't want to use anything else. It's handy to manage everything using systemctl

alyandon• 2 months ago

That and systemd having actually useful man pages.

the_real_cher3• 2 months ago

This is such a modern view. People used to HATE systemd when it first came out, but I always liked it and knew people would eventually come around and its nice to see they finally did!

egorfine15• 2 months ago

Some people are stubborn and refuse to see how obviously superior systemd is to the old ways. Me included.

weaksauce2• 2 months ago

the thing for me is I started using the init system and while it was fine it always felt brittle for some reason. systemd feels solid and robust like it was well thought out. maybe i'm off base and didn't know how to use init effectively but it was my feeling.

that and cron always felt fragile too with a lot of quirks and limitations you had to work around instead of being a robust thing from the start.

eichin2• 2 months ago

Arguably they (we :-) were right at the time. Around Ubuntu 16.04, the journal was Hot Garbage - to keep a production system working (as in, "didn't randomly stop logging, didn't regularly corrupt logs, didn't uncontrollably fill the disk because none of the limit options actually worked") we eventually backported about 30 fixes from newer versions - by 22.04 or so it was "fit for purpose" out of the box, but earlier than that it earned every bit of hatred it got.

guilhas2• 2 months ago

People still hate systemd

First it caused lots of issues. And didn't deliver anything significant

But the biggest issue has always been architectural, the way systemd keeps absorbing existing projects, and functionality. That keep adding to the more than 1 million lines of C monolith, that can burden progress in the futre

But as long people can replace any of systemd tool, for a tool they like better, all good

Personally I am now using desktop/server distros without systemd, and there is nothing that I miss, everything works... cuda/llama.cpp/steam/docker...

And commands always have to google them anyway, or find in history...

egorfine15• 2 months ago

Some people see it differently. As in: after using it they don't want to use it. I hate systemd with passion.

But that's because I'm old because obviously systemd-* is the only right way and everyone else who see things differently is a pundit.

bjoli2• 2 months ago

I hard disagree. Previously I could use what I knew about Linux commands to read logs and administer the systemm. Systemctl knowledge does not generalize.

I have done scheme all my life, which is why I prefer shepherd. Not only is it in a syntax that i can use elsewhere, I get completion in Emacs.

bjoli2• 2 months ago

To continue on this: info use systemd on most of my systems. I dont mind. But despite having used it for about 14 years, I still have to read the manual of journalctl.

Systemctl is OK, but I really do not like that respect of the utilities.

rconti• 2 months ago

I still hate journald logging though

sureglymop3• 2 months ago

There are still some weird things/choices in its design I don't fully understand.

For example, why do unit definitions have to be actual files on disk? Then, all of these files are reloaded when the daemon reloads, not just changed ones. But, why couldn't there be an API letting me add units programmatically? (There kind of is but it's constrained/inflexible)

Or, why can't I declare multiple units in the same file? It's really designed around the filesystem instead of abstracting at a different level, which is a choice I don't think is smart. It's not like it follows the unix philosophy though.

As for the format used for unit definitions, I wish TOML had been around so they could have had something sensible...

paulddraper4• 2 months ago

You can add units programmatically. Google it!

lanycrost2• 2 months ago

it's so, but overall linux is not following linux philosophy in many other places, and do it far before systemd. Many tools even running under unix not doing so like gcc, x.org, etc.

NikhilVerma• 2 months ago

I have a Canon printer, I actually can't trust that their print nozzle won't get jammed up after sitting idle for a while. So I had claude setup a systemd script to print a picture of my dog every week, I ensure it has enough CMYK spectrum to stress the printer. Its a nice surprise every monday as I sit on my desk to see a sudden picture pop up from the printer :)

tdeck• 2 months ago

I wish printers could have a mode like this to print random images from an album, or a calendar, rather than wastefully draining ink into a sponge every few days.

If nothing else, maybe it could be some kid's high school science fair project idea.

sunrunner2• 2 months ago

How about printing a QR code for a randomly generated private key for Satoshi Nakamoto's Bitcoin wallet, then every few days you get a tiny moment of excitement, hope, and then disappointment. It's still wasteful, but it could pay off big time?

magicalhippo• 2 months ago

Dad had an Deskjet 720 or something like that.

It sat unused and powered off for a couple of years after he passed, until I needed a color print.

Didn't do anything but hook it up to power and print. Took about 1/5 of a page until all colors were back in action, after that it printed about 20 pages flawlessly.

RicoElectrico• 2 months ago

I was about to recommend a cheap OKI LED color printer (I think C322dn); alas they withdrew from consumer market :/ The colors are super nice and uniform, even if the maximum resolution is only 600 dpi - and the toner won't dry out, which was my brother's crucial purchase criterion; we had HP inkjet clogged more than once.

ThePowerOfFuet• 2 months ago

Laser printers are your friend. The savings on consumables alone will make it pay for itself.

hmng• 2 months ago

Not to mention more water resistant, when printing things like envelopes.

tobyhinloopen2• 2 months ago

Epson Ecotank. I’ve been using mine for years and I only had to buy new ink once.

And I printed a lot of photos, notes, documents, etc

criddell• 2 months ago

Laser printers are great for documents, but not very good for photos.

I have an ink jet printer that I like. I don't print very often (average a couple pages per week) but when I do it's a mix of documents and photos. The ink isn't cheap, but the quality seems good and for the amount I print the expense is minor.

tombert• 2 months ago

I used to do something similar with an old Samsung ML-2010 back when I was in college the first time around.

I think it was software and not hardware, but for some reason when I had that printer hooked up to my computer and idle for more than a week, it would simply stop printing. I probably could have dug through logs and figured it out, but I instead set up a cron job to print a test page every Monday and Thursday. The test pages would just have something on the top that said something like LOL PRINTER WORKS.

This wasn't actually as wasteful as it sounds; I was taking a boatload of math courses and needed tons of scratch paper in order to do my problems. Since it was scratch paper and would eventually end up in the trash anyway, I would usually prioritize doing my problems on failed prints and/or test prints, and I would usually exhaust those and then use blank paper afterwards.

frays• 2 months ago

I've been using Linux for over 20 years, systemd for over 10.

Yet there's always something new to learn and actually consider as another useful tool.

egorfine15• 2 months ago

I'm using Linux for about 30 years and apparently we were all wrong using cron for decades.

paulddraper4• 2 months ago

Not wrong, but there’s room for improvement!

sammy2255• 2 months ago

I've converted all my crons to systemd timers+services over the past year but cant help but think it's sort of.. less tangible than cron

Like imagine trying to explain systemd timers and services and unit files to a beginner.

darkwater• 2 months ago

Like imagine trying to explain systemd timers and services and unit files to a beginner.

I think it's... easier? Like "systemd is the place where your system manages all the processes it needs to run. Part of those processes can be run on a schedule, or on a timer, and you define them using this simple text file".

PunchyHamster5• 2 months ago

cron is easier for easy stuff ("just run this every 10 minutes") but harder for hard stuff ("run it every 8 hours but with randomized offset so not all machines at once do it, but also if machine was down when it should run, run it immediately").

It is also easier to debug as every job gets its own log rather than trying to write to system mailer nobody had set up with the job errors

thomashabets215• 2 months ago

I haven't used systemd timers enough to disagree, but

Ambiguous $PATH settings make cron script execution difficult to predict.

What makes you say that? You can set the PATH right in the crontab. Is that harder to "predict" than it being set in /etc/bashrc, ~/.bashrc, ~/.profile, ~/.bash_profile, /etc/systemd/…, or wherever else?

You might feel cool knowing the scheduling grammar by heart

I've used Linux since 1994 and I don't know it by heart. But luckily it's pre-printed in the crontab as comments:

    # For more information see the manual pages of crontab(5) and cron(8)
    # 
    # m h  dom mon dow   command

You just put numbers aligned with the titles.

The rest of the complaints, sure. Next time I need a cronjob, I'll try it out.

jchw2• 2 months ago

The main nice thing about the environment in systemd is that it is standard and mostly a blank slate, whereas at least for me I was always getting bit by the fact that the environment in Crontab was completely different from say, the environment inherited by supervisord or sysvinit scripts. In systemd the actual unit that gets executed is the same regardless of what triggers it, so there is no gap.

That does require you to still know what the default environment is, but it is a mostly completely clean environment, without any influence from any shell.

I'd have to concur that I agree this is an advantage of systemd.

skydhash2• 2 months ago

I use cron in OpenBSD and it's a deterministic environment and mostly clean[0]. I like that instead of having other subsystems creep in.

[0] https://man.openbsd.org/crontab.5#ENVIRONMENT

simoncion16• 2 months ago

That does require you to still know what the default environment is, but it is a mostly completely clean environment, without any influence from any shell.

Odd. This script

  #!/bin/bash
  
  set > /tmp/set.txt

when scheduled like so

  * * * * * $HOME/bin/testCronScript.sh

Produces this file in /tmp/set.txt which has had a handful of values (HOME, UID, etc) lightly redacted prior to posting here -to remove PII or for length- but its keys are entirely untouched:

  BASH=/bin/bash
  BASHOPTS=<redacted because long>
  BASH_ALIASES=()
  BASH_ARGC=()
  BASH_ARGV=()
  BASH_CMDS=()
  BASH_LINENO=([0]="0")
  BASH_LOADABLES_PATH=/usr/local/lib64/bash:/usr/lib64/bash
  BASH_SOURCE=([0]="/home/user/bin/testCronScript.sh")
  BASH_VERSINFO=<redacted bash 5.3.x>
  BASH_VERSION=<redacted bash 5.3.x>
  DIRSTACK=()
  EUID=13370
  GROUPS=()
  HOME=/home/user
  HOSTNAME=hostname
  HOSTTYPE=x86_64
  IFS=$' \t\n'
  LANG=en_US.utf8
  LOGNAME=user
  MACHTYPE=x86_64-pc-linux-gnu
  OPTERR=1
  OPTIND=1
  OSTYPE=linux-gnu
  PATH=/usr/bin:/bin:/usr/sbin:/sbin
  PPID=1337
  PS4='+ '
  PWD=/home/user
  SHELL=/bin/sh
  SHELLOPTS=braceexpand:hashall:interactive-comments
  SHLVL=1
  TERM=dumb
  UID=13370
  USER=user
  _=/home/user/bin/testCronScript.sh

Seems pretty clean to me. Even when I run this via /etc/crontab, rather than as a user cron job:

  * * * * * root /home/user/bin/testCronScript.sh

I get effectively the same results.

Maybe your distro's default cron environment was bad, and you never bothered to check and unset the badness? I'd be surprised if they were unable to make the default environment for Timer Units to be bad.

jerf• 2 months ago

"You just put numbers aligned with the titles."

That is not a fair summarization of their point because that is not the grammar. There's commas, slashes, asterisks, combinations, and then if you want randomization you need to put it in the command itself because cron can't do it. (Some crons can, but it's not a general capability of cron.) Writing a non-trivial cron spec is not easy.

eqvinox2• 2 months ago

How do you express those things in a systemd timer? E.g. run something 4x per day, */6 in cron.

pkal• 2 months ago

I am familiar with the syntax, so I am biased ("*/3" and "12,14,20" makes sense if you are familiar with Unix tools), but it is still more intuitive to me than the systemd unit file syntax and usage. I know that I just have to edit /etc/cron or throw any executable file into /etc/cron.d/monthly and it will work on my system, but I cannot write a systemd timer file from scratch without looking it, and to do that I first have to find the directory where the other examples are located. /etc/systemd doesn't appear to be it.

This is generally my only real complaint about systemd. I don't care if it is too monolitic, written in C or whatever, I just want a straightforward syntax for straightforward operations. I'd like it if systemd could recognize if a .target file is a shell script and just do "the right thing". Perhaps it would make sense for a timer file to recognize cron syntax as well. Or at least allow for a kind of extensibility so that I can have it supported.

If systemd had a little more respect for existing conventions, I am pretty sure it wouldn't be so controversial. After all, system administrators like it because they use it all the time, but a regular, full-timer user like me, who only deals with it when something is broken or have to use it as a means-to-an-end to set something up, then all friction is annoying and bad UX. (And no, using Nix is not the solution)

jeroenhd• 2 months ago

Having had to work on an application supposedly supporting cron expressions: the numbers are just the basic parts of the language.

When someone inputs something ridiculous like "5,3/4 4-8,11 1 4,5,6,9-11 */2" you get to enjoy the fun of reverse engineering what they meant (it's never what they actually wrote).

And that's before you get to all the extensions supported in some cron environments (but not all).

I find systemd timers a lot more manageable. Things like having control over whether or not long-running jobs are allowed to overlap and the ability to run tasks between start-finish rather than a fixed time window are major improvements for me. At some point my VPS went down because the backup job ran into some kind of symlink loop and cron just kept spawning more and more backup tasks even though none of them finished.

Having to re-write commands and scripts because CRON had its own special PATH was also a pain point, but the same can be true for some types of systemd timers. But: you can execute those timers manually if you want instead of updating the crontab to trigger in 30 seconds and simply waiting.

ink_13• 2 months ago

5,3/4 4-8,11 1 4,5,6,9-11 */2

What's so hard about "At 5 minutes past the hour and every 4 minutes, starting at 3 minutes past the hour, at 04:00 AM through 08:59 AM and 11:00 AM, on day 1 of the month, every 2 days of the week, only in April, May, June, and September through November"?

(I used https://crontab.cronhub.io/ to decode it, to be fair)

networked• 2 months ago

Complex expressions are one of the things I don't like in cron. On Debian/Ubuntu servers, I just bite the bullet with systemd timers. On my workstation, I have a personal job scheduler that feels easier and more fun to tinker with. The scheduler uses Starlark functions instead. For example:

  # Run if at least a day has passed since the last run
  # and it isn't the weekend.
  def should_run(finished, timestamp, dow, **_):
      return dow not in [0, 6] and timestamp - finished >= one_day

This was inspired by GNU mcron. In mcron, jobs can calculate the next time they should run using Guile (https://www.gnu.org/software/mcron/manual/mcron.html#Guile-S...):

  (job
     '(next-minute-from
        (next-hour (range 0 24 2))
        '(15))
     "my-program")

I found mcron's scheduling counterintuitive and decided I wanted a function that returned a boolean. I can tentatively recommend it.

thomashabets215• 2 months ago

Per other comments though, it looks like systemd's syntax when you want to specify something that's not just that one number is at least as complex.

Is your example (which I agree, looks cryptic) any less cryptic in systemd?

I asked jippity, and it said this:

    [Timer]
    OnCalendar=*-04,05,06,09,10,11-01 04..08,11:03/4,05:00
    OnCalendar=Sun,Tue,Thu,Sat *-04,05,06,09,10,11-* 04..08,11:03/4,05:00

To which I have to go: "what?"

Things like having control over whether or not long-running jobs are allowed to overlap

With cron that's just prefixing the command with `flock -n <lock>`, but sure the "pick somewhere to put the lock" is probably better with systemd.

Having to re-write commands and scripts because CRON had its own special PATH

Why? Wouldn't you just put that in the crontab? I don't even see this as different. It's in the cron config or the systemd timer config.

The other improvements you mentioned seem good.

egorfine15• 2 months ago

I've used Linux since 1994

Same here.

We are now considered old and therefore irrelevant. The new generation uses timers and couldn't care less about cron that has served us just fine for decades.

I use cron and my general attitude towards LP and systemd is very similar to the attitude of LP and systemd to us.

sophacles7• 2 months ago

Total n00b here. My first linux install was pretty recently, in late 1996 or early 1997 (sometime that winter).

I just don't get it. Like is the core sentiment "How dare they address obvious system shortcomings"? Is it "I learned once and how dare you think I'm capable of learning again"? Is it "I want others to suffer the way I did to learn job scheduling"?

cron did a job, but had shortcomings. Systemd addresses many of those shortcomings. One day something else will come along and address the shortcomings of systemd, and no one will care about systemd nostolgia. This is how technology is supposed to work: making progress and fixing the shortcomings of the past generation. It's not a religion, we don't have to maintain the weird old ways from the 80's, your soul won't be saved by cron or corrupted by systemd.

nailer• 2 months ago

But luckily it's pre-printed in the crontab as comments

That's true, but most people don't know the numbered manual sections, so they get the docs for the cron table command not the cron table config file.

skydhash2• 2 months ago

That's true, but most people don't know the numbered manual sections, so they get the docs for the cron table command not the cron table config file.

No `man man`? ;)

PunchyHamster5• 2 months ago

problem with vars is that they apply to any subsequent entry in the file so you need to take that into consideration; the nice thing about timers is that all settings are self contained and not affected by previous entries. The standard /10 and similar cron expressions also have thundering herd problem when on bunch of servers, tho some variants like in Jenkins use variant H/10 (H standing for hash) where the thing is randomly shifted in time to not hit same minute on same server/job

another benefit is having logs in one place for the job; cron's "send a mail when there is any amount of output text" is just annoying behaviour, but also only place to get the job output unless you redirect it somewhere. Also starting from timer vs just doing systemctl start job.service is the same so easier to debug

other than that the few improvements in how to specify run time have been pretty useful.

For example, setting timer as "persistent" will mean any run "lost" to machine powered off will just be ran next time after boot, so you can have job on your PC that is just "run backup at 2AM" and if you turn it off before that you get the backup done first thing in the morning

There is also both random, and fixed (depending on machine UUID) random delay so avoiding thundering herd problem with backups is also pretty convenient.

There is even option to wake a device for the job if necessary tho the problem of shutdown is left to the user. And picking whether to start counting to next timer from previous one or from the job's end.

What I would like also is to have job summary page ("hey this job was done X times but failed Y times") but that's probably better left to external tooling

You can set the PATH right in the crontab. Is that harder to "predict" than it being set in /etc/bashrc, ~/.bashrc, ~/.profile, ~/.bash_profile, /etc/systemd/…, or wherever else?

There is* a common trap as the cron PATH is usually just /usr/bin:/bin so anything in /usr/local/bin, or in /sbin won't be there.

thomashabets215• 2 months ago

There is* a common trap as the cron PATH is usually just /usr/bin:/bin so anything in /usr/local/bin, or in /sbin won't be there.

There will always be a default. Is systemd timer's default inherently correct for all users any more than cron's is?

I'm just playing devil's advocate here, but why not just change cron, then? Good for the goose is good for the gander?

mike_hock3• 2 months ago

What makes you say that? You can set the PATH right in the crontab.

OK but I don't want to hardcode $PATH in the crontab just so I can test the cronjob. Barring the hardcode, $PATH is one thing when cron runs and another when you try out the command yourself. systemctl start foo.service starts the command inside with the same environment as when the timer fires so you know it'll work the same.

On the flip side, your cron job will run at the time you specify in the crontab. Your systemd timer, on the other hand, may fire at the specified time (and most of the time, it will), but it can also suddenly stop firing once it has fired on a February 29th and then never fire again, due to logic bugs in systemd, or it may or may not fire when you "restart" the timer unit, due to logic bugs in systemd (that's when it only has OnCalendar, so yes, definitely a bug).

thomashabets215• 2 months ago

$PATH is one thing when cron runs and another when you try out the command yourself.

Why would that be different with systemd timers? If my ~/.bashrc adds /opt/foo/bin, that's also not part of the systemd timer's PATH, right?

But I guess you're saying the ability to trigger the systemd timer off-schedule is the difference? Yeah, it's annoying with cron to have to temporarily set the trigger two minutes into the future. :-P

Not sure adding that feature justifies a complete rewrite, but certainly a nice addition.

due to logic bugs in systemd

Yeah my main gripe with systemd and other Lennartware is the extremely low implementation quality, not necessarily the ideas. Though the idea of killing tmux/screen on logout is downright criminal. And the fd passing nonsense[1] for system services is clearly just the idea of a child that found a tool and is misusing it.

[1] which is an awesome and underused feature (https://blog.habets.se/2025/10/The-strange-webserver-hot-pot...), but completely misapplied by systemd.

themafia• 2 months ago

But luckily it's pre-printed in the crontab

    man 5 crontab

Way easier.

emmelaich• 2 months ago

You can set the PATH right in the crontab.

Yes, but people don't. I've had to debug other's crontabs many times over the last umpteen years.

thomashabets215• 2 months ago

But how is that different with systemd timers?

Two environments that set the PATH differently won't have the same value set, either way.

Is this about "yes, but cron doesn't let me trigger through its environment, and systemd timers do"?

thayne3• 2 months ago

I wouldn't say that the PATH is ambiguous, but cron does have some problems with PATH:

- the default value is missing some values you would expect, like /use/local/bin and /usr/sbin for root.

- on some distributions (for example Arch Linux) the man page doesn't even say what the default path is, or recommend setting it.

- if you need to add something to the path for a single script, you either need to wrap it with a call to env, set it in a wrapper script, or set the path before the entry and reset it afterwards

- you can't use ~ or $HOME in the path, you have to write out the full absolute path. Which is particularly annoying for user crontabs.

Sure, it isn't too hard to work around those, but IMO systemd timers are a better experience, especially since the default uses the same path as all your other services.

thomashabets215• 2 months ago

- the default value is missing some values you would expect, like /use/local/bin and /usr/sbin for root.

What do you mean by "you would expect", that doesn't also apply to systemd timers? /opt/foo/bin is not in the path. Would you expect that?

And if this is an objective problem, can we just change the cron default PATH?

- on some distributions (for example Arch Linux) the man page doesn't even say what the default path is, or recommend setting it.

Send a PR. This doesn't seem like an inherent problem.

- if you need to add something to the path for a single script, you either need to wrap it with a call to env, set it in a wrapper script, or set the path before the entry and reset it afterwards

Or on the line, right?

    * * * * * FOO=bar $HOME/bin/foo.sh

The line can get long, but is this really a problem?

- you can't use ~ or $HOME in the path, you have to write out the full absolute path. Which is particularly annoying for user crontabs.

This is incorrect. You can definitely use $HOME in user crontabs.

I'm still not seeing something that warrants a rewrite. (except what you did not mention, which is the ability to run "trigger this now" as a missing feature)

cmsj• 2 months ago

Is there a way yet to force-trigger a timer? There wasn't the last time I used them, which I found to be super annoying for testing them.

Biganon• 2 months ago

It's covered in the article, you can simply start the unit that would be started by the timer.

Oh but it won't appear in the timer-specific logs, I guess...

baggy_trough• 2 months ago

In decades of trying, I do not believe there was one time that I ever got a cron job to work properly in the first attempt. Systemd timers are a godsend.

kayson• 2 months ago

I love systemd timers! I've slowly moved all of my ansible-deployed cron jobs to timers (now just an ansible copy!). The integration with journalctl, especially in a newer OS like Debian 13 where syslog is gone, is really nice. It's also really nice to be able to start the service manually for debug. Having a cron job that didn't work was an annoying exercise in copy/pasting or writing an extra shell script. Don't even get me started on the black hole of cron job stdout. I can monitor systemd services like I already do and get a notification on failure.

I've noticed more and more open source projects recommending timers as a deployment method and I think that's great!

egorfine15• 2 months ago

more and more open source projects recommending timers

I am perfectly happy with projects recommending timers as long as I can ignore them and use cron.

sunshine-o• 2 months ago

This is actually something that I like in systemd.

I am dealing with mostly non systemd system: BSD, Alpine, termux On BSD anacron works well, but I do not why I am always running into problems with the cronie anacron implementation. And it is very hard to debug.

I would really like a simple modern cron/anacron alternative.

Cronicle looked cool but it is node.js, a bit heavy and being replace now by their new product called xyOps anyway.

mkesper2• 2 months ago

There's another big feature: You're not relying on the time zone to which the server was set (like with cron) but can explicitly specify a time zone:

https://www.freedesktop.org/software/systemd/man/latest/syst...

6031769• 2 months ago

Of course you can do this trivially in cron as well. It is what the CRON_TZ variable is for.

mkesper2• 2 months ago

This is a GNU extension so not portable.

eichin2• 2 months ago

hmm, when did that get added? Last time I checked, the only timezone you could specify was UTC (which was one more than cron supported, but still insufficient.)

mindcrime• 2 months ago

I haven't always been the biggest fan of systemd in some regards, but I will say that I mostly agree with this sentiment. I've almost completely quit using cron, and now favor systemd timers for scheduled jobs - at the "system" level anyway. I might still embed Quartz for scheduling that's scoped to a particular application or something.

Why? It's one of those fuzzy and somewhat hard to explain things. The systemd approach just maps more cleanly to my mental model of "how things should work" I guess. And maybe some of it is that I did indeed experience plenty of " Ambiguous $PATH settings make cron script execution difficult to predict" in the past, although it's not just that.

I won't sit here and claim that systemd timers are necessarily better than cron in any universal / objective sense. But they've won me over, for what it's worth.

chuckadams• 2 months ago

I believe one of the major distro lines (redhat or debian, I forget which) uses systemd-cron, where cron is just a thin wrapper around systemd. You get more power from writing the unit files directly, but if all you ever need is a simple cron job, you have the old interface still available.

MathMonkeyMan• 2 months ago

Yep, I use this for a @reboot job and a few regular jobs on my home server. I use user crontabs, so I can get around the "unknown shell/path/etc." by prefixing every job with

    /some/shell -l myjob.sh

or sometimes

    . ~/.profile && cd /some/where && ./job >>cron.log 2>&1

pull_my_finger• 2 months ago

I'm fully ready to drink the "just let systemd do all the things" kool-aid, but I would love to see some sort of introductory/tutorial info into some of the things it can do other than services - i.e. containers and timers. I know man pages exist, but it would be nice if there was more scannable intro out there.

htx80nerd2• 2 months ago

btw that xz hack only effect systemd distros

dmuth• 2 months ago

stdout and stderr output often ends up in a black hole

Ain't that the truth. Literally every crontab I've written for the last 10 years has had this in it:

2>&1 | logger -t cron-WHATEVER

...and that does a pretty good job of capturing anything that the script emits and making it easy to grep for in syslog the following morning.

But I'm still amazed at how many crontabs I run across that don't capture any output at all.

ninkendo• 2 months ago

The “standard” is for the output to go to your user’s mail box. You know, that thing you check with the “mail” command and has a user interface shockingly similar to `ed`. You check that all the time, right? Right?

It’s… certainly a product of its time. (I have my system mailer set up to actually send mail to my Gmail account, with authenticated SMTP via API keys, which I did 15 years ago and have no recollection of how I even did it. It still works… somehow. I don’t even use Gmail any more, and I’ll be damned if I have to figure out how to do it with fastmail, and lord knows doing unauthenticated old-school SMTP is just gonna get sent to fastmail’s black hole, so that idea ain’t gonna work either.)

7e• 2 months ago

systemd is great all around. Don’t listen to the boomers complaining about it because their cheese was loved.

jjtheblunt• 2 months ago

(typo, i think). cheese was moved?

guilhas2• 2 months ago

They should listen to other people talking about their knowledge about cheese, of the single one they know, the cheese slices from the supermarket

progforlyfe• 2 months ago

This is a very good intro to systemd timers -- I think you convinced me to finally start using them. Love the "list-timers" thing as well. With cron, it never seemed easy to me to get a picture of all the cron jobs running on a box. I'd need to check crontab for all users, as well as /etc/cron.d/, as well as the daily/hourly/monthly directories.

And in fact I do have a use-case for needing to run something ~5 minutes after the system boots and then every ~12 hours onward from there. It's great that systemd timers has me covered!

tylerjl2• 2 months ago

Thanks for the kind words! Especially given how ubiquitous systemd is now, skilling up on the toolbox with commands like `systemd-analyze` and `systemctl list-timers` feels super valuable.

simoncion16• 2 months ago

You will love SystemD [0] timers until they fuck you over in an entirely inscrutable way and the SystemD maintainers don't care to either fix the problem or update the docs to warn of the shortcoming.

One of our customers called in with a production down incident caused by a full disk. We got a copy of the VM and took a look. Investigation revealed that / was full because /var/log was full and that our 'logrotate' timer unit that was scheduled to run once a day had run either exactly never or exactly once... I can't remember which. Further investigation revealed no difference in software load or configuration between this VM and a VM that had a functional logrotate timer unit. Exactly one VM out of hundreds of identical VMs at this site (and many multiples of that at other customer's sites) were affected by this. Advising the customer to clear out /var/log and reboot did not unstick 'logrotate', and none of the diagnostics or fixes we could find anywhere unstuck it. Once "systemd-crond" decided to never schedule this job ever again, it stuck to that decision.

After a lot of searching, we found an open bug report from a year or three prior where someone reported exactly the same symptoms and was scheduling a unit with pretty much the same set of unit configuration flags that we were using. The conversation from the core devs ran through the pattern that one gets used to seeing when one runs into SystemD bugs that are caused by extremely complex unanticipated interactions between parts of the project: "That's not a bug, only an idiot would want that to work.", "Oh, we don't document that that's not supposed to work?", "Wow, okay, yeah, I can see how that maybe should work. That it doesn't sure does seem weird.", "Having said that, I don't know if it's supposed to work, or if it's unsupported. Someone should really either document that or fix it."... and then the behavior is neither fixed nor documented. [1] Absent any actual explanation for the failure, we ended up swizzling the options in our 'logrotate' unit and praying that satisfied whatever gremlin arose from the depths to trouble our customer.

SystemD contains an enormous -and ever-growing- amount of accidental complexity, and has a set of core maintainers who are generally disinterested in either documenting the places where one or more complex systems bind together to cause stop-the-world problems or fixing the systems involved so that they don't bind up. It's a fine project until it's very, very suddenly not, and then you're absolutely SOL. If you're lucky, you can shuffle around what you're doing [2] and hope that avoids the problem. [3]

[0] Some folks use the spelling "SystemD" to mock the project. I use the spelling "SystemD" to distinguish between "the entire systemd project" and systemd(1). I do this because some folks will make a claim like "systemd is very, very small and self-contained. I don't understand why anyone would say otherwise.", but what they are actually saying is that systemd(1) is a fairly small program that doesn't do all that much when run as PID 1. It sucks minor amounts of ass that the project and the program it runs as PID 1 share the same name, but what can you do?

[1] No, I don't have a link to the open bug report. This was more than a year ago, so the bug ID has been long forgotten.

[2] The term of art for this practice is "wave a dead chicken at it".

[3] Plus, like, even disregarding most of the rest of my report... how in the hell do you design a cron that knows a job is scheduled to be run periodically, can tell you how long it has been since it last ran, but never manages to run it? To me, that's unforgivable. It's a "You had one job!"-tier cockup.

Eduard4• 2 months ago

this issue?

https://github.com/systemd/systemd/issues/6680

simoncion16• 2 months ago

Yeah, quite possibly... that one seems familiar! Your Google-fu is quite strong.

htx80nerd2• 2 months ago

The conversation from the core devs ran through the pattern that one gets used to seeing when one runs into SystemD bugs that are caused by extremely complex unanticipated interactions between parts of the project
SystemD contains an enormous -and ever-growing- amount of accidental complexity, and has a set of core maintainers who are generally disinterested in either documenting the places where one or more complex systems bind together to cause stop-the-world problems or fixing the systems involved so that they don't bind up.

excellent comment. thx for the long form. im sure it was fueled by excessive frustration.

imagine my surprise to learn that Systemd was causing my long standing frustration with changing my dns settings. and further surprise to learn that server admins have this same issue and many switch away from using systemd-resolved.

TacticalCoder2• 2 months ago

... imagine my surprise to learn that Systemd was causing my long standing frustration with changing my dns settings. and further surprise to learn that server admins have this same issue and many switch away from using systemd-resolved.

That's introductory course to systemd's shenanigans. People are going to tell you that you're not doing it properly, that there's of course this setting (unless that other setting takes precedence etc.), yada, yada, yada.

If I really have to suffer systemd the first thing I do is manually edit /etc/resolv.conf and then chattr +i /etc/resolv.conf.

And of course remove/purge systemd-resolved.

Not only is it "always the DNS" but then things turn from bad to worse when "it's the DNS, but with systemd".

Removing systemd-resolved is the first step. The second one is moving to an OS or a Linux distro that doesn't have systemd at all.

egorfine15• 2 months ago

FTFY: You will love SystemD until they fuck you over

egorfine15• 2 months ago

We have used cron perfectly fine for decades and it served us well within its very clear limitations.

But now obviously we were so blind and wrong all this time and the only true solution is of course systemd.

bigbuppo2• 2 months ago

Thank Lennart you degenerate apostates are finally starting to see the light of His glorious creation. Hallowed be thy systemd-journald.

bakugo2• 2 months ago

Has it actually served you well? Because it hasn't served me well at all.

I am not the biggest fan of systemd, but today I will always reach for a systemd timer over cron simply due to the sheer amount of bad experiences I've had with cron. Hours upon hours wasted trying to troubleshoot crons that weren't working due to some stupid obscure issue, having to use dirty hacks to monitor for success or retry failed jobs.

A few years ago I was trying to run a very simple bash script with cron and the script just died halfway through for no reason. Nothing in logs, worked fine when run directly, but in cron it just stopped halfway through a loop. Never figured out the cause, just gave up and used a timer instead, which worked fine. Never touched cron again after that.

The ease and convenience of monitoring and troubleshooting alone are worth switching over.

egorfine15• 2 months ago

Let me state once again: "within its very clear limitations".

Once you learn that env in cron is not same as in your shell and once you learn to redirect output to loggers - it works just fine.

It would be a lie to say that I never debugged cron and sure it's annoying.

and the script just died halfway through for no reason

Unrelated to cron. Bad script.

mschuster913• 2 months ago

But now obviously we were so blind and wrong all this time and the only true solution is of course systemd.

Come on, dude. That's unnecessarily polemic.

cron et al have served us for decades, yes. But that doesn't mean that cron is the solution that needs to accompany us until the heat death of the universe or year 2038, whatever comes first.

I agree, the systemd folks haven't exactly been the best when it comes to PR or when it comes to being even near feature parity with what they tried to replace. But now, they aren't just at feature parity, they surpassed plain old cron.

Maybe it is time to lay cron to rest, at least slowly.

egorfine15• 2 months ago

that doesn't mean that cron is the solution that needs to accompany us until the heat

Yeah I agree.

systemd folks haven't exactly been the best when it comes to PR

It's deeper than that. Systemd folks are enemies of Linux. First, it's "fuck your opinion, do as we say" attitude which makes me want to throw away everything that comes from that poisonous well. Second, it's the embrace and extinguish strategy employed by the systemd project. And third, systemd author is up to no good: https://news.ycombinator.com/item?id=46784572

tim-projects• 2 months ago

After reading this article I'm convinced that what we need is systemd timers fronted by a vibe coded crontab -e emulator.

Coz it's looks crazy complicated to set them up.

TacticalCoder2• 2 months ago

But now obviously we were so blind and wrong all this time and the only true solution is of course systemd.

Oh nooooo... I've been so wrong. Seen the direction most Linux distro took I decided to move to VMs (VMs which runs systemd-less systems), OCI containers (where by definition PID 1 is not systemd) and now an hypervisor to run systemd Linux VM but I'm now into... An hypervisor that is precisely not Linux (so no systemd at all).

I sinned. So now maybe it's time to buy Microsoft stocks, praise Windows [ini] config files, and venere the Linux PID 1 god with its tentacles meddling with every part of the Linux system.

Or not.

bigbuppo2• 2 months ago

That would assume I like systemd in the first place.

MarkusWandel• 2 months ago

Does systemd ship with something to upgrade your cron jobs for you? That would be the friendly way. Write your old school cron jobs, and then a script that converts them to do things the systemd way, documenting its steps, i.e. I created this file and this is why. Friendly "I help you do things better" rather than standoffish "your way is obsolete, you need to do it our way". Oh wait. I get it. LLM agents can do exactly that for you can't they. Another way I'm behind the curve.

I have knocked together a systemd service or three based on google copypasta. But generally, for cron jobs, why make it complicated? One line in /etc/crontab and done. I generally call an encapsulation script that sets the right environment variables, uses absolute paths, captures stdout/stderr if required and so on. I just want the simplest possible way to launch that script on a schedule.

Bender• 2 months ago

I will use what I am comfortable with and so should others. CronD, SystemD, atD, multiple conditional checks in a shell script, whatever tickles your fancy. There is no wrong answer, just document what you did and add a comment. Comments are permitted in cron. If someone keeps putting complex obfuscated time structures into cron make them decipher their incantation and keep nagging them until they keep it simple, comment their cron entries or until they and their manager resign.

For what it's worth there are usually web apps popping up that can decipher goofy cron time/date incantations. [1] This one has a git repo in the top right, not my repo. Maybe clone it just in case their site goes away some day.

[1] https://crontab.cronhub.io/

pjot• 2 months ago

After years of using orchestration tools like airflow and dagster so many lightbulbs have just lit up in my head.

I wish documentation for tools would explain their abstractions concepts in terms of its primitives.

Great post, thanks!

jpcfl• 2 months ago

Prime Time for a Timer Primer

It's pronounced, "primmer."

OJFord2• 2 months ago

TIL that's the standard US pronunciation. I thought you must be joking, referencing something else: OP's title works with BrE pronunciation at least.

https://en.wiktionary.org/wiki/primer#Pronunciation

KAMSPioneer• 2 months ago

Wait, really? I'm a native Midwestern/Great Plains American English speaker (I remember reading the Harry Potter books as a kid and wondering why all the -er words were spelled wrong) and I say "PRY-mer." I have never heard anyone say "PRIM-mer" in my life.

Am...am I being punk'd...?

louiskottmann• 2 months ago

And you immediately lose the ability to do `crontab -l` on any server to know its scheduled tasks.

Now you get to look around the myriad of places where you can put systemd files, and figure out which ones are base services and which ones are custom, with no general convention to go about it. Nope.

arter45• 2 months ago

systemd list-timers

With —-all

TazeTSchnitzel• 2 months ago

If you had read the article, you would have seen its answer to this.

Eduard4• 2 months ago

  /etc/crontab
  /etc/cron.d/*
  /etc/cron.hourly/*
  /etc/cron.daily/*
  /etc/cron.weekly/*
  /etc/cron.monthly/*
  /var/spool/cron/crontabs/*

zbentley2• 2 months ago

Bad memories. I particularly enjoyed fighting with third-party programs that installed system cronjobs in the various tabs, and having to remember to go and find them after package upgrades and try to figure out how to robustly identify when their processes were running so my other cronjobs wouldn't overload or clobber state, since the third-party-installed jobs didn't play along with any lockfile-based coordination we used. Wants/WantedBy/Requires are godsends by comparison.

encoderer• 2 months ago

I setup a few systemd timers last year and created https://systemd.guru to play with different options in OnCalendar expressions.

t435622• 2 months ago

It may be a disastrous comment to make but I think I like cron better! A tool designed for a particular job etc.... :/

sophacles7• 2 months ago

I designed a tool for flying. It's only designed for flying. It is based on the principles of the brick.

yoYo2R4• 2 months ago

Cron. Initial release May 1975; 51 years ago

It is succesfully flying 51 year. And will work next 50 years. Systemd probably will changes syntax in next 2 years. Modern development mindset: if tool is not rewritten last month - it is outdated and we need to reinvent it. Probably using blockchanin and AI.

supriyo-biswas• 2 months ago

I wonder what happened with the heading, it was okay before, and then was mutilated since.

porridgeraisin• 2 months ago

I am not the greatest fan of most of systemd's features. I will always prefer it tho since I just view it as a "packaging format". The same way I view docker. It is just that it happens to be the format that a lot of software is using and I have almost no headache integrating services, timers, logging and such of software I install. Without systemd its a mighty pain. Everyone uses the same one thing and that makes me overlook any drawbacks of the model. Only if the entire system was set up by me and mostly ran my software and I was getting paid for it, I might not use systemd.

But one feature of systemd I will absolutely stand by is nspawn. It's just beautiful.

miladyincontrol• 2 months ago

Yeah nspawn has to be one the most underrated (and 100% optional ofc) components.

BrenBarn• 2 months ago

I like these systemd things but I always find it annoying how I have to create multiple separate files (like a file for the service and another for the timer, or similar if I need a socket file). In theory this is more flexible but in practice it's vanishingly rare that I need the same service to be accessible to more than one timer. It would be nice if there were some alternative compound format that could combine the timer and service into one.

tmp104232884422• 2 months ago

I command you to love systemd timers!

(Yeah, they're pretty useful, especially after you get an LLM to write all the boilerplate for you. The boilerplate was the main reason I preferred crontab before.)

arikrahman• 2 months ago

Refreshing to see a positive opinion with regards to systemd. Incidentally, my favorite way to spawn jobs, is well, the job spawn command in nushell.

tylerjl2• 2 months ago

Hey everyone, author here. I spotted the hn traffic a little late but I'm happy for any feedback or comments and will try and address the top-level comments as I can.

(Aside: I wrote this article early last month but it caught on only just recently. For better or worse, touching a third rail topic like systemd seems like a sure-fire way to elicit strong and numerous reactions both positive and negative.)

naikrovek• 2 months ago

Article author lost me when he demonstrated that two files are needed to schedule something.

That is silly.

opan• 2 months ago

And yet. You probably shouldn't use literal cron (or its more modern cousins) for scheduled tasks! In 2026 there are more modern options available

What are people on non-systemd distros like Guix System, Void, PCLinuxOS, and so on using for this? Is there still something better to use than cron?

Admittedly I never learned cron, I use a lot of `sleep` and `countdown` for relative delays instead. Just earlier today I set up a 12h countdown followed by opening a URL with xdg-open since I expect a release around then and don't want to forget. I also threw in a little notify-send command in case my browser isn't visible, I should see that pop up. Considered using espeak, but don't wanna scare myself and/or ruin my watching experience if I'm watching a video at that time.

yoYo2R4• 2 months ago

What are people on non-systemd distros like Guix System, Void, PCLinuxOS, and so on using for this? Is there still something better to use than cron?

Instead of `sleep` you can use `at`. But for scheduling `cron` is still the best.

Package: at

at, batch, atq, atrm - queue, examine, or delete jobs for later execution

egorfine15• 2 months ago

What are people on non-systemd distros like Guix System, Void, PCLinuxOS, and so on using for this?

We have used and still use cron for decades. It does it's job and does it well.

notorandit• 2 months ago

In 2026 there are more modern options available

More modern doesn't mean any better or more powerful.

I for one hate this need for going "more modern" without having clear and factual advantages.

Elhana• 2 months ago

Same shit, but you need to create 3 files instead of one line in crontab.

Love systemd timers

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