shlomo

This article includes a script that will perform a consistent snapshot of an XFS-formatted EBS drive (in linux).

http://alestic.com/2009/09/ec2-consistent-snapshot

Consistent snapshots are needed when the disk contains multiple files that must be kept in sync with each other - such as a database's data files and the journal. If your DB gets its disk snapshotted while these files are out of sync, the DB will need to recover the missing data by replaying the journal. Not all DB's can do this reliably for all types of changes (e.g. MySQL's MyISAM engine is fragile in this regard). So you need to make sure that the files in the snapshot all reflect a consistent state of the disk.