Messages in this thread |  | | | From | Kyle Moffett <> | | Subject | Re: Back to the future. | | Date | Thu, 3 May 2007 12:53:48 -0400 |
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On May 03, 2007, at 11:10:47, Pavel Machek wrote: > How mature is freezing filesystems -- will it work on at least > ext2/3 and vfat?
I'm pretty sure it works on ext2/3 and xfs and possibly others, I don't know either way about VFAT though. Essentially the "freeze" part involves telling the filesystem to sync all data, flush the journal, and mark the filesystem clean. The intent under dm/LVM was to allow you to make snapshots without having to fsck the just- created snapshot before you mounted it. > What happens if you try to boot and filesystems are frozen from > previous run?
If you're just doing a fresh boot then the filesystem is already clean due to the dm freeze and so it mounts up normally. All you need to do then is have a little startup script which purges the saved image before you fsck or remount things read-write since either case means the image is no longer safe to resume.
If the kernel is later modified to purge all filesystem data (dcache/ pagecache) during snapshot and effectively remount and reopen all the files by path during restore then you could remove that requirement. You'd just need to make sure that the restore-from-disk scripts did an fsck or journal-restore before reloading the old kernel data.
Cheers, Kyle Moffett - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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