3x faster linux boot with e4rat

http://e4rat.sourceforge.net/

by jewel • 14 years ago

190 100 14 years ago

e4rat.sourceforge.net

johnhartigun• 14 years ago

Does the debian package work in Ubuntu?

diggan4• 14 years ago

Yes, you might need to remove ureadahead though.

diggan4• 14 years ago

Good tutorial about how to use e4rat: http://www.howtogeek.com/69753/how-to-cut-your-linux-pcs-boo...

hamoid• 14 years ago

Would it make a difference with SSD drives?

diggan4• 14 years ago

No, it moves the files used in the startup to a closer sector and won't speed up your booting time if you're using SSD discs.

rbanffy6• 14 years ago

By placing the files together in the memory you may get some extra performance, but it depends on how your SSD is internally organized - you may have some locality effects if the drive pre-fetches more than the block you called for into a cache faster than the flash memory.

jeltz• 14 years ago

Sequential reads are faster than random even on SSD drivers, so it could help but I am not sure how much.

Iv• 14 years ago

Oh ? Why is that ? SSD still need to address every memory block, don't they ? Or do they have a faster DMA-like mode where you can send the instruction "give me the next 96KB starting at address X ?

diggan4• 14 years ago

I'm not sure if a SSD drive have any moving parts and therefor will not benefit from E4rat.

wtallis• 14 years ago

With an SSD, the bottleneck for booting is usually hardware detection and initialization, not reading data off the disk. My system takes about 4-5 seconds from the time the bootloader hands off control to the kernel to the time the kernel starts executing the initrd, and another 6-7 seconds to mount the SSD and hard drive, establish the network connection, start system services, and present a login prompt (though starting X and changing resolutions takes another second or two on top of that). I probably can't make that more than 20% faster without getting a faster DHCP server or tweaking various delays and timeouts that exist for good reasons.

dwc• 14 years ago

Laptop: open lid and resume. Server: RAID startup dwarfs OS startup.

Does super fast booting matter much these days? It's just about ceased to matter to me completely.

acabal2• 14 years ago

Linux still has lots of problems with suspend/hibernate/resume on laptops (Oneiric broke hiberanate on my laptop for example), so booting is still kind of important for that reason.

Resume from hibernate is another area where I'd like to see improvements. I hibernate instead of suspend because I never know if I'll make it back to an outlet in time.

javert4• 14 years ago

Sounds like a problem with Ubuntu, really, not Linux.

kijin• 14 years ago

I try to avoid using sleep/resume when I'm away from home, because it partially defeats the purpose having full-disk encryption on my laptop. A thief who steals it when it's powered off has no access to my files. On the other hand, a thief who steals it when it's asleep might be able to get around the login once it wakes up.

So yes, it sucks to wait 30-40 seconds for a reboot.

idleloops2• 14 years ago

While I like a fast boot, you've go to get these things a little into perspective, a minute to the desktop isn't that bad.

1amzave• 14 years ago

Wouldn't the ideal solution then be to modify the OS to purge the disk encryption keys from memory on sleep? If you're concerned about unencrypted file contents in memory, purge the page/buffer cache while you're at it.

Then ask the user to re-enter the key on resume and get back to business...am I missing some obvious problem here?

I guess depending on one's level of paranoia, there might be sensitive non-file data sitting in memory...you could then quit the applications you're concerned about, and have the kernel wipe any unallocated memory before sleeping (I think by default it doesn't wipe pages until they're reallocated to something else, on Linux at least).

Obviously with flushing caches and quitting applications and so forth you're trading off some of the benefit of keeping the system alive, but presumably it still beats a cold boot every time you come back to your laptop.

there• 14 years ago

Which operating system? On OS X Lion, you can make the system hibernate when the lid is closed, writing encrypted memory to disk. Slower wakeup times than suspend, but quicker than a full startup.

https://news.ycombinator.com/item?id=3785762

teach2• 14 years ago

I wish my Ubuntu desktop booted in 40 seconds. Thanks to btrfs, a reboot is a 30-minute affair.

hammersend2• 14 years ago

As has been mentioned full disk encryption loses a lot of its efficacy if you just put your laptop in standby all the time. I'd add that as long as a faster boot doesn't compromise your system in other ways, why wouldn't you want it?

gst• 14 years ago

It doesn't - if done right.

When hibernating my laptop it writes the memory contents into swap - which is also encrypted. Yes, de-hibernating is slower if contents need to be read from disk. OTOH it's still faster than booting from disk.

TheBoff• 14 years ago

I this bizarre problem that whenever my fridge turns on, it wakes my laptop from sleep, even if the laptop's not plugged in.

The joys of student life!

derefr• 14 years ago

Is this similar to OSX's Hot File Adaptive Clustering, then?

obtu4• 14 years ago

The OSX feature apparently notices files which are slowly appended to (downloads) and defragments them. It does not reallocate a set of files (such as the ones touched at boot) to be adjacent on disk, which is what e4rat does.

driverdan2• 14 years ago

It's an interesting project. I wish we had it 5+ years ago when it mattered.

The only place I'd use a spinning disk as my primary drive is on a server and that's something you rarely boot. If you're not using an SSD skip a month of Starbucks and buy one. Disk IO is far and away the biggest bottleneck for most users. An SSD will increase your productivity profoundly.

Danieru2• 14 years ago

I did buy one, then it broke.

Once you factor in the re-installs the latency of spinning rust looks a bit better.

mdonahoe• 14 years ago

My SSD makes for a nice drink coaster.

Karunamon• 14 years ago

Don't buy garbage SSDs, and make sure your system is utilizing them correctly. Putting swap on an SSD = horrible idea.

reitzensteinm2• 14 years ago

Which SSD did you buy?

I'd only trust an Intel at this point, though even they're not much more reliable than a traditional hard drive on average (now that they've shipped a few buggy firmware revisions).

driverdan2• 14 years ago

All drives can fail. Not including servers I've managed I estimate I've had more than 10 hard drives fail, all of which were well below the manufacturer's stated MTBF.

My first SSD (low to mid range) failed within the first 3-6 months but the replacement has been going for almost 2 years now.

ethermal• 14 years ago

almost all of my spinning disks in the last 20+ years have failed. Some right away, some in a few months, some in a few years but they all have failed.

ww520• 14 years ago

SSD is still expensive for the mass. Fast boot for Linux is still very much relevant for the few who can afford SSD. It's great for embedded devices using Linux.

dripton• 14 years ago

I bought a 64 GB Crucial M4 SSD for a boot drive for my Linux desktop about a year ago. About a month ago, it started giving read/write errors eventually leading to kernel panics. (Didn't lose any data.) I switched back to the hard drive.

I don't see a huge difference in productivity for normal desktop use. An SSD is definitely quieter, and somewhat faster, but caching means most of us are already not hitting the disk that hard. (Obviously if you're doing intensive work with big data that doesn't cache well, that's a different story.)

jdboyd• 14 years ago

For most people, I would say not to get a flash drive until the memory has been maxed out. At that point, a flash drive will probably help more than the price difference on a faster CPU.

rbanffy6• 14 years ago

> I wish we had it 5+ years ago when it mattered.

You know... Some people still use spinning metal. Also, my notebook is also my main work machine and it only fits one 2.5" device inside it (albeit I'm tempted to experiment with running the OS off an SD card, if not for speed (which is unlikely) for battery life. I don't care if Emacs comes up in 2 seconds instead of four.

Even with SSDs, by keeping the files in contiguous blocks (I would assume this program may even purposely not do it - as it would make sense to interleave blocks of files that are opened simultaneously during the boot process in the order the blocks - not the files - are called in) you may get some extra mileage out of your storage - you'd have a simpler structure for each file - instead of a list of blocks (or extents) you'd have the whole thing in a single extent.

rogerbinns2• 14 years ago

Many recent laptops have mini-PCIe slots. You can put a credit card sized SSD in that slot as your boot disk, and then use the 2.5" drive bay for spinning media with lots of space. Here is an example one from Intel with pictures: http://www.newegg.com/Product/Product.aspx?Item=N82E16820167...

rplnt2• 14 years ago

Switching my laptop disk to SSD was probably the best investment I made (laptop related anyways). 64GB or even 96GB SSDs are quite cheap . You can buy an external, USB powered casing for the (presumably) big platter disk and use it like that.

pygy_2• 14 years ago

If your laptop has an optical dive which you don't use, you may be able to get the best of both world.

Put your HDD in the optcal drive bay, and the SSD in the main bay. Adapter frames exist, at least for Apple laptops.

mirashii• 14 years ago

There actually were projects which did this years ago. One of them was called fcache (by Jens Axobe), which had the same goal but achieved it in a filesystem independent fashion by using an extra partition and placing all data read during boot linearly in the extra partition.

exim• 14 years ago

Well, I only boot my home/work computer once a day. I only do hibernate/dehibernate during the day, which is quite fast.

cgoddard• 14 years ago

I wish [I] had it 5+ years ago when it mattered [to me].

Most people don't drop 75+ dollars on Starbucks a month, and rent, food and healthcare expenses are a tad more important than buying faster, more expensive hard drives. Free software optimizations would actually be very much appreciated by a great deal of people with scarce disposable income.

This reminds me of that article in a New York publication a while back written by a woman marveling at how much money she saved by not eating out every meal. Like the advice given wasn't an obvious necessity already for 95+% of people.

sciurus3• 14 years ago

Note that if you're using Ubuntu you're using ureadhaead, which does something similar to minimize seeks during boot.

https://wiki.archlinux.org/index.php/Ureadahead

rcthompson2• 14 years ago

Then why are there deb files for Ubuntu? I don't think they're doing exactly the same thing, since e4rat is using specific features of the Ext4 filesystem.

Edit: Actually, the directions say to remove Ureadahead when installing e4rat, so maybe they are quite similar.

yason2• 14 years ago

AFAIK, ureadahead just keeps track of which files/blocks are touched during bootup/startx and pre-reads them into a cache at the very beginning of the boot sequence so you will effectively boot from cache.

This still requires seeking to several semi-random areas of the disk while prereading which e4rat is fixing by physically moving the needed blocks adjacent to eachother.

hello_asdf• 14 years ago

The easiest way I've found to increase boot speed and application load even under heavy system load is to use the pf kernel patchset. With a properly configured kernel using BFS, BFQ, and LZMA compression, my system is amazingly fast. Even when compiling and both cores at my laptop are at 100% my system is fully usable. If you have a Macbook Pro my kernel configs are here: https://github.com/meinhimmel/kernel-configs

dneb7• 14 years ago

I saw a demo of this at Intel Labs on a Windows machine about 15 years ago and it was very impressive. I don't think they optimized startup, but application launch was incredibly fast with their disk layout optimization.

Isn't this essentially what DiskKeeper does on Windows?

maaku2• 14 years ago

I don't know about DiskKeeper, but I believe it's part of the "Lenovo Enhanced Experience" on ThinkPads. Amazingly, my factory install with crapware booted from pressing BIOS to Windows desktop in just over 7 seconds. I haven't been able to get my clean install below 10 seconds, I think because I'm missing the filesystem tweaking.

ThePinion• 14 years ago

Just did this on an old Inspiron 1545 with Ubuntu 12.04 on it and I'm already noticing major improvement in both boot time and the apps I open frequently (also with the help of preloader and zram)

I followed this guide: http://www.howtogeek.com/69753/how-to-cut-your-linux-pcs-boo...

Although note, at the part where it says push CTRL+ALT+F1 to get to a new terminal login, that didn't work for me. I had to go to the default one (CTRL+ALT+F7) and type "logout" and then go to CTRL+ALT+F6.

I have a web page I keep track of common things I do to my Ubuntu installs (shameless plug: http://ubuntu.mindseeder.com) and I'm definitely going to add this so I don't forget!

obtu4• 14 years ago

I wonder how much improvement that brings over standard ureadahead (see yason in this thread for how they differ). For zram, no need for a ppa, a zram-config package has been added in precise.

yason2• 14 years ago

Ten years ago, BeOS booted in ten seconds without any special tricks. That was on late 90's and early 00's hardware. Certainly it didn't access hundreds of megabytes of libraries and files in order to boot as a modern Linux does, but it was also specifically designed that way even by the contemporary standards.

And don't get me started about the 16-bit era... Machines were slower then but using them was generally faster.

m_st• 14 years ago

That's why people love tablets and smartphones. You're much faster using them to check your mails or weather, etc than using a topnotch PC. [Now of course that doesn't include booting but when did you reboot your tablet or smartphone the last time?]

rbanffy6• 14 years ago

30 years ago, my Apple II booted into a REPL in less than one second. 3 if you needed disk support.

And that was on a 1 MHz 8-bit processor.

There were people who could toggle a bootstrap loader into an Altair in less time than a modern x86 PC takes to boot.

moeffju• 14 years ago

So when will we see this in our smartphones? I don't understand and, frankly, find it ridiculous that I have to wait about a minute or up to 90 seconds for my smartphone to boot, a device that is completely flash-memory based and that has no variability in hardware. I still remember the article about that industrial Linux PC that booted in less than one second, including initializing video4linux and two cameras etc., simply by optimizing kernel parameters, boot order, and driver timeouts. That must have been 2005 or so. Now it's 2012 and my phone takes longer to boot than my laptop (late 2010 MBP w/ SSD).

3x faster linux boot with e4rat

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