Hi all, I''m currently doing backups by doing a btrfs snapshot, then rsync the snapshot to my backup location. As I have a lot of small files and quite some changes between snapshots, this process is taking more and more time. I looked at "btrfs find-new", which is promissing, but I need something to track deletes and modifications too. Also, while this will help the initial comparison phase, most time is still spent on the syncing itself, as a lot of overhead is caused by the tiny files. After finding some discussion about it here: http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external-mailing-lists-3/backuppc-21/using-rsync-for-blockdevice-level-synchronisation-of-backupp-100438 I found that the official rsync-patches tarball includes the patch that allows syncing full block devices. After the initial backup, I found that this indeed speeds up my backups a lot. Ofcourse this is meant for syncing unmounted filesystems (or other things that are "stable" at the block level, like LVM snapshot volumes). I tested backing up a live btrfs filesystem by making a btrfs snapshot, and this (very simple, non-thorough) turned out to work ok. My root subvolume contains the "current" subvolume (which I mount) and several backup subvolumes. Ofcourse I understand that the "current" subvolume on the backup destination is broken/inconsistent, as I change it during the rsync run. But when I mounted the backup disk and compared the subvolumes using normal file-by-file rsync, they were identical. Can someone with knowledge about the on-disk structure please confirm/reject that subvolumes (created before starting rsync on the block device) should be safe and never move by themselves? Or was I just lucky? Are there any things that might break the backup when performed during rsync? Like creating/deleting other subvolumes, probably defrag isn''t a good idea either :) Or any incompatible mount options (compression, space_cache, ssd) Thanks for any comments on this. Mathijs -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs- > owner@vger.kernel.org] On Behalf Of Mathijs Kwik > > I''m currently doing backups by doing a btrfs snapshot, then rsync the > snapshot to my backup location. > As I have a lot of small files and quite some changes between > snapshots, this process is taking more and more time. > I looked at "btrfs find-new", which is promissing, but I need > something to track deletes and modifications too. > Also, while this will help the initial comparison phase, most time is > still spent on the syncing itself, as a lot of overhead is caused by > the tiny files.No word on when this will be available, but "btrfs send" or whatever it''s going to be called, is currently in the works. This is really what you want.> After finding some discussion about it here: > http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external- > mailing-lists-3/backuppc-21/using-rsync-for-blockdevice-level- > synchronisation-of-backupp-100438When you rsync at the file level, it needs to walk the directory structure, which is essentially a bunch of random IO. When you rsync at the block level, it needs to read the entire storage device sequentially. The latter is only a possible benefit, when the amount of time to walk the tree is significantly greater than the time to read the entire block device. Even if you rsync the blocklevel device, the local rsync will have to read the entire block device to search for binary differences before sending. This will probably have the opposite effect from what you want - Because every time you created and deleted a file, every time you overwrote an existing block (copy on write) it still represents binary differences on disk, so even though that file was deleted, or several modifications all yielded a single modification in the end, all the bytes of all the deleted files and all the file deltas that were formerly occupied will be sent anyway. Unless you always zero them out, or something. Given that you''re talking about rsync''ing a block level device that contains btrfs, I''m assuming you have no raid/redundancy. And the receiving end is the same. Also if you''re rsyncing the block level device, you''re running underneath btrfs and losing any checksumming benefit that btrfs was giving you, so you''re possibly introducing risk for silent data corruption. (Or more accurately, failing to allow btrfs to detect/correct it.)> I found that the official rsync-patches tarball includes the patch > that allows syncing full block devices. > After the initial backup, I found that this indeed speeds up my backups a lot. > Ofcourse this is meant for syncing unmounted filesystems (or other > things that are "stable" at the block level, like LVM snapshot > volumes).Just guessing you did a minimal test. Send initial image, then make some changes, then send again. I don''t expect this to be typical after a day or a week of usage, for the reasons previously described.> I tested backing up a live btrfs filesystem by making a btrfs > snapshot, and this (very simple, non-thorough) turned out to work ok. > My root subvolume contains the "current" subvolume (which I mount) and > several backup subvolumes. > Ofcourse I understand that the "current" subvolume on the backup > destination is broken/inconsistent, as I change it during the rsync > run. But when I mounted the backup disk and compared the subvolumes > using normal file-by-file rsync, they were identical.I may be wrong, but this sounds dangerous to me. As you''ve demonstrated, it will probably work a lot of the time - because the subvols and everything necessary to reference them are static on disk most of the time. But as soon as you write to any of the subvols - and that includes a scan, fsck, rebalance, defrag, etc. Anything that writes transparently behind the scenes as far as user processes are concerned... Those could break things.> Thanks for any comments on this.I suggest one of a few options: (a) Stick with rsync at the file level. It''s stable. (b) Wait for btrfs send (or whatever) to become available (c) Use ZFS. Both ZFS and BTRFS have advantages over one another. This an area where zfs has the advantage for now. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Oct 23, 2011 at 4:08 PM, Edward Ned Harvey <kernel@nedharvey.com> wrote:>> From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs- >> owner@vger.kernel.org] On Behalf Of Mathijs Kwik >> >> I''m currently doing backups by doing a btrfs snapshot, then rsync the >> snapshot to my backup location. >> As I have a lot of small files and quite some changes between >> snapshots, this process is taking more and more time. >> I looked at "btrfs find-new", which is promissing, but I need >> something to track deletes and modifications too. >> Also, while this will help the initial comparison phase, most time is >> still spent on the syncing itself, as a lot of overhead is caused by >> the tiny files. > > No word on when this will be available, but "btrfs send" or whatever it''s going to be called, is currently in the works. This is really what you want. > > >> After finding some discussion about it here: >> http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external- >> mailing-lists-3/backuppc-21/using-rsync-for-blockdevice-level- >> synchronisation-of-backupp-100438 > > When you rsync at the file level, it needs to walk the directory structure, which is essentially a bunch of random IO. When you rsync at the block level, it needs to read the entire storage device sequentially. The latter is only a possible benefit, when the amount of time to walk the tree is significantly greater than the time to read the entire block device.My test was just a 10G block device filled with random files between 512b and 8k While this is a contrived example, in this case a block level rsync is way way way faster. It''s not just the tree-walking that''s slow, I guess there''s some per-file overhead too.When not using rsync but plain dd, it''s even faster (at the expense of more writes, even when unneeded), since it can almost transfer data at the maximum write speed for the receiver.> > Even if you rsync the blocklevel device, the local rsync will have to read the entire block device to search for binary differences before sending. This will probably have the opposite effect from what you want - Because every time you created and deleted a file, every time you overwrote an existing block (copy on write) it still represents binary differences on disk, so even though that file was deleted, or several modifications all yielded a single modification in the end, all the bytes of all the deleted files and all the file deltas that were formerly occupied will be sent anyway. Unless you always zero them out, or something.I understand. A block copy is not advantageous in every situation. I''m just trying to find out if it''s possible for the situations where it is beneficial.> > Given that you''re talking about rsync''ing a block level device that contains btrfs, I''m assuming you have no raid/redundancy. And the receiving end is the same.Yup, in my example I synced my laptop ssd to an external disk (usb3).> > Also if you''re rsyncing the block level device, you''re running underneath btrfs and losing any checksumming benefit that btrfs was giving you, so you''re possibly introducing risk for silent data corruption. (Or more accurately, failing to allow btrfs to detect/correct it.)Not sure... I''m sure that''s the case for in-use subvolumes, but shouldn''t snapshots (and their metadata/checksums) just be safe?> > >> I found that the official rsync-patches tarball includes the patch >> that allows syncing full block devices. >> After the initial backup, I found that this indeed speeds up my backups a lot. >> Ofcourse this is meant for syncing unmounted filesystems (or other >> things that are "stable" at the block level, like LVM snapshot >> volumes). > > Just guessing you did a minimal test. Send initial image, then make some changes, then send again. I don''t expect this to be typical after a day or a week of usage, for the reasons previously described. > > >> I tested backing up a live btrfs filesystem by making a btrfs >> snapshot, and this (very simple, non-thorough) turned out to work ok. >> My root subvolume contains the "current" subvolume (which I mount) and >> several backup subvolumes. >> Ofcourse I understand that the "current" subvolume on the backup >> destination is broken/inconsistent, as I change it during the rsync >> run. But when I mounted the backup disk and compared the subvolumes >> using normal file-by-file rsync, they were identical. > > I may be wrong, but this sounds dangerous to me. As you''ve demonstrated, it will probably work a lot of the time - because the subvols and everything necessary to reference them are static on disk most of the time. But as soon as you write to any of the subvols - and that includes a scan, fsck, rebalance, defrag, etc. Anything that writes transparently behind the scenes as far as user processes are concerned... Those could break things.I understand there are harmful operations, that''s why I''m asking if it is known exactly what those actions are. I''m not writing to the snapshots (only to my "current" subvol) during rsync/dd and I make sure not to rebalance or defrag (basically don''t use any btrfs progs). I understand that "current" will be corrupt on the backup destination, but it would be great to know that all other subvolumes should be safe. For this case (my laptop) I can stick to file-based rsync, but I think some guarantees should exist at the block level. Many virtual machines and cloud hosting services (like ec2) provide block-level snapshots. With xfs, I can freeze the filesystem for a short amount of time (<100ms), snapshot, unfreeze. I don''t think such a lock/freeze feature exists for btrfs, but if btrfs guarantees all snapshots are stable as long as you don''t use any btrfs tools while snapping, it''s not needed either. Ofcourse I understand there''s a difference between an instant block snapshot and a dd/rsync session that takes a few minutes, but if the dont-use-dangerous-operations conditions are met, it shouldn''t matter for snapshots that aren''t used. Also, I can see how future applications might want to use btrfs for providing history, or other special purposes that they now write their own b-tree code for. If the above holds true, block backups would have no issues backing up this data, while file backups might lead to enormous redundancy as files/blocks shared between multiple subvolumes get unCOWed on the destination.> > >> Thanks for any comments on this. > > I suggest one of a few options: > (a) Stick with rsync at the file level. It''s stable. > (b) Wait for btrfs send (or whatever) to become available > (c) Use ZFS. Both ZFS and BTRFS have advantages over one another. This an area where zfs has the advantage for now.Thanks for your advice, Like I said, for me, right now, sticking to tried-and-tested file-based rsync is just ok. But I hope to get some insights into other possibilities. btrfs send sounds cool, but I sure hope this is not the only solution, as I described a few scenarios where block-level copies have advantages. Mathijs> >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Oct 23, 2011 at 09:45:10AM +0200, Mathijs Kwik wrote:> Hi all, > > I''m currently doing backups by doing a btrfs snapshot, then rsync the > snapshot to my backup location. > As I have a lot of small files and quite some changes between > snapshots, this process is taking more and more time. > I looked at "btrfs find-new", which is promissing, but I need > something to track deletes and modifications too. > Also, while this will help the initial comparison phase, most time is > still spent on the syncing itself, as a lot of overhead is caused by > the tiny files. > > After finding some discussion about it here: > http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external-mailing-lists-3/backuppc-21/using-rsync-for-blockdevice-level-synchronisation-of-backupp-100438 > > I found that the official rsync-patches tarball includes the patch > that allows syncing full block devices. > After the initial backup, I found that this indeed speeds up my backups a lot. > Ofcourse this is meant for syncing unmounted filesystems (or other > things that are "stable" at the block level, like LVM snapshot > volumes). > > I tested backing up a live btrfs filesystem by making a btrfs > snapshot, and this (very simple, non-thorough) turned out to work ok. > My root subvolume contains the "current" subvolume (which I mount) and > several backup subvolumes. > Ofcourse I understand that the "current" subvolume on the backup > destination is broken/inconsistent, as I change it during the rsync > run. But when I mounted the backup disk and compared the subvolumes > using normal file-by-file rsync, they were identical. > > Can someone with knowledge about the on-disk structure please > confirm/reject that subvolumes (created before starting rsync on the > block device) should be safe and never move by themselves? Or was I > just lucky? > Are there any things that might break the backup when performed during rsync? > Like creating/deleting other subvolumes, probably defrag isn''t a good > idea either :)The short answer is that you were lucky ;) The big risk is the extent allocation tree is changing, and the tree of tree roots is changing and so the result of the rsync isn''t going to be a fully consistent filesystem. With that said, as long as you can mount it the actual files in the snapshot are going to be valid. The only exceptions are if you''ve run a filesystem balance or removed a drive during the rsync. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Oct 23, 2011 at 6:05 PM, Chris Mason <chris.mason@oracle.com> wrote:> On Sun, Oct 23, 2011 at 09:45:10AM +0200, Mathijs Kwik wrote: >> Hi all, >> >> I''m currently doing backups by doing a btrfs snapshot, then rsync the >> snapshot to my backup location. >> As I have a lot of small files and quite some changes between >> snapshots, this process is taking more and more time. >> I looked at "btrfs find-new", which is promissing, but I need >> something to track deletes and modifications too. >> Also, while this will help the initial comparison phase, most time is >> still spent on the syncing itself, as a lot of overhead is caused by >> the tiny files. >> >> After finding some discussion about it here: >> http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external-mailing-lists-3/backuppc-21/using-rsync-for-blockdevice-level-synchronisation-of-backupp-100438 >> >> I found that the official rsync-patches tarball includes the patch >> that allows syncing full block devices. >> After the initial backup, I found that this indeed speeds up my backups a lot. >> Ofcourse this is meant for syncing unmounted filesystems (or other >> things that are "stable" at the block level, like LVM snapshot >> volumes). >> >> I tested backing up a live btrfs filesystem by making a btrfs >> snapshot, and this (very simple, non-thorough) turned out to work ok. >> My root subvolume contains the "current" subvolume (which I mount) and >> several backup subvolumes. >> Ofcourse I understand that the "current" subvolume on the backup >> destination is broken/inconsistent, as I change it during the rsync >> run. But when I mounted the backup disk and compared the subvolumes >> using normal file-by-file rsync, they were identical. >> >> Can someone with knowledge about the on-disk structure please >> confirm/reject that subvolumes (created before starting rsync on the >> block device) should be safe and never move by themselves? Or was I >> just lucky? >> Are there any things that might break the backup when performed during rsync? >> Like creating/deleting other subvolumes, probably defrag isn''t a good >> idea either :) > > The short answer is that you were lucky ;)That''s why I only try this at home :)> > The big risk is the extent allocation tree is changing, and the tree of > tree roots is changing and so the result of the rsync isn''t going to be > a fully consistent filesystem.Nope, I understand it''s not fully consistent, but I''m hoping for consistency for all subvols that weren''t in use during the sync/dd.> > With that said, as long as you can mount it the actual files in the > snapshot are going to be valid. The only exceptions are if you''ve run a > filesystem balance or removed a drive during the rsync.Do I understand correctly that as long as I don''t defrag/balance or add/remove drives (my example is just about 1 drive though), there''s a chance the result isn''t mountable, but if it _is_ mountable, all subvolumes that weren''t touched during the rsync/dd should be fine? Or is there a chance that some files/dirs (in a snapshot volume) are fine, but others are broken? In other words: do I only need to check the destination to be mountable afterwards or does that by itself mean not enough. You mentioned 2 important trees - tree of tree roots - extent allocation tree My root subvolume contains only subvolumes (no dirs/files), 1 of which is mounted with -o subvol, the rest are snapshots. Am I correct to assume the tree of tree roots doesn''t change as long as I don''t create/remove subvols? And for the extent allocation tree, can I assume that all changes to extent allocation will be related to files/dirs changing on the currently in-use subvolume? All extents that contain files in any of the snapshots will still be there as changes to those files in "current" will be COWed to new extents. So the risk is not that extents are marked "free" when they aren''t, but I might end up with extents that are marked in-use while they are free. As I expect "current" to become corrupt in the destination, I will remove the subvolume there. Will that take care of the extent allocation tree? Or will there still be extents marked "in use" without any subvolume/dir/file pointing at it? If so, this is probably something that the future fsck can deal with?> > -chrisThanks, Mathijs> > > >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011-10-23, 17:19(+02), Mathijs Kwik: [...]> For this case (my laptop) I can stick to file-based rsync, but I think > some guarantees should exist at the block level. Many virtual machines > and cloud hosting services (like ec2) provide block-level snapshots. > With xfs, I can freeze the filesystem for a short amount of time > (<100ms), snapshot, unfreeze. I don''t think such a lock/freeze feature > exists for btrfs[...] That FS-freeze feature has been moved to the vfs layer so is available to any filesystem now. You can either use xfs_io (see -F option to "freeze" for foreign FS) like for xfs FS or use fsfreeze from util-linux. Note that you can thaw file systems with a sysrq combination now. (for instance with xen using "xm sysrq vm j"). For block level snapshots, see also ddsnap (device mapper target unfortunately no longer maintained) and lvm of course (but doesn''t scale well with several snapshots). -- Stephane -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> From: Mathijs Kwik [mailto:mathijs@bluescreen303.nl] > Sent: Sunday, October 23, 2011 11:20 AM > > > Also if you''re rsyncing the block level device, you''re running underneath > btrfs and losing any checksumming benefit that btrfs was giving you, so > you''re possibly introducing risk for silent data corruption. (Or more > accurately, failing to allow btrfs to detect/correct it.) > > Not sure... I''m sure that''s the case for in-use subvolumes, but > shouldn''t snapshots (and their metadata/checksums) just be safe?Nope. The whole point of checksumming is like this: All devices are imperfect. They have built-in error detection and correction. Whenever an error occurs (which is often) the drive tries to silently correct it (reread) without telling the OS. But the checksumming in hardware is rather weak. Sometimes you''ll get corrupt data that passes the hardware test and reaches the OS without any clue that it''s wrong. I find that a typical small business fileserver (10 sata disks) hits these approx once a year. Filesystem checksumming is much stronger (lower probability to silently allow an error). Like randomly selecting a single molecule twice consecutively amongst all the molecules in the solar system. Like much less likely to occur than the end of the human race, etc. So when the silent errors occur, filesystem checksumming definitely detects it, and if possible, corrects it. If you are reading the raw device underneath btrfs, you are not getting the benefit of the filesystem checksumming. If you encounter an undetected read/write error, it will silently pass. Your data will be corrupted, you''ll never know about it until you see the side-effects (whatever they may be). While people with computers have accepted this level of unreliability for years (fat32, ntfs, ext3/4, etc) people are now beginning to recognize the importance on a greater scale. Once corrupted, always corrupted. People want to keep their data indefinitely.> Thanks for your advice, > Like I said, for me, right now, sticking to tried-and-tested > file-based rsync is just ok. But I hope to get some insights into > other possibilities. btrfs send sounds cool, but I sure hope this is > not the only solution, as I described a few scenarios where > block-level copies have advantages.There is never a situation where block level copies have any advantage over something like btrfs send. Except perhaps forensics or espionage. But in terms of fast efficient reliable backups, btrfs send has every advantage and no disadvantage compared to block level copy. There are many situations where btrfs send has an advantage over both block level and file level copies. It instantly knows all the relevant disk blocks to send, it preserves every property, it''s agnostic about filesystem size or layout on either sending or receiving end, you have the option to create different configurations on each side, including compression etc. And so on. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011-10-24, 09:59(-04), Edward Ned Harvey: [...]> If you are reading the raw device underneath btrfs, you are > not getting the benefit of the filesystem checksumming. If > you encounter an undetected read/write error, it will silently > pass. Your data will be corrupted, you''ll never know about it > until you see the side-effects (whatever they may be).[...] I don''t follow you here. If you''re cloning a device holding a btrfs FS, you''ll clone the checksums as well. If there were errors, they will be detected on the cloned FS as well?> There is never a situation where block level copies have any > advantage over something like btrfs send. Except perhaps > forensics or espionage. But in terms of fast efficient > reliable backups, btrfs send has every advantage and no > disadvantage compared to block level copy.$ btrfs send ERROR: unknown command ''send'' Usage: [...] (from 2011-10-12 integration branch). Am I missing something?> There are many situations where btrfs send has an advantage > over both block level and file level copies. It instantly > knows all the relevant disk blocks to send, it preserves every > property, it''s agnostic about filesystem size or layout on > either sending or receiving end, you have the option to create > different configurations on each side, including compression > etc. And so on.[...] That sounds like "zfs send", I didn''t know btrfs had it yet. My understanding was that to clone/backup a btrfs FS, you could only clone the block devices or use the "device add" + "device del" trick with some extra copy-on-write (LVM, nbd) layer. -- Stephane -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs- > owner@vger.kernel.org] On Behalf Of Stephane CHAZELAS > > 2011-10-24, 09:59(-04), Edward Ned Harvey: > [...] > > If you are reading the raw device underneath btrfs, you are > > not getting the benefit of the filesystem checksumming. If > > you encounter an undetected read/write error, it will silently > > pass. Your data will be corrupted, you''ll never know about it > > until you see the side-effects (whatever they may be). > [...] > > I don''t follow you here. If you''re cloning a device holding a > btrfs FS, you''ll clone the checksums as well. If there were > errors, they will be detected on the cloned FS as well?You''re right and I''m right. You will have read them, transferred them, and written them without checking them. So any corruption at this point is undetected. But later when you mount the destination FS, you would then be checking checksums again.> > There is never a situation where block level copies have any > > advantage over something like btrfs send. Except perhaps > > forensics or espionage. But in terms of fast efficient > > reliable backups, btrfs send has every advantage and no > > disadvantage compared to block level copy. > > $ btrfs send > ERROR: unknown command ''send'' > Usage: > [...] > > (from 2011-10-12 integration branch). Am I missing something?As previously mentioned in this thread, btrfs send (or whatever it will be called) is not available yet. My suggestion to the OP of this thread is to use rsync for now, wait for btrfs send, or switch to zfs. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011-10-25, 07:46(-04), Edward Ned Harvey: [...]> My suggestion to the OP of this thread is to use rsync for now, wait for > btrfs send, or switch to zfs.[...] rsync won''t work if you''ve got snapshot volumes though (unless you''re prepared to have a backup copy thousands of times the size of the original or have a framework in place to replicate the snapshots on the backup copy as soon as they are created (but before they''re being written to)). To backup a btrfs FS with snapshots, the only option seems to be to copy the block devices for now (or the other trick mentionned earlier). -- Stephane -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs- > owner@vger.kernel.org] On Behalf Of Stephane CHAZELAS > > rsync won''t work if you''ve got snapshot volumes though (unless > (etc blah)Please read the OP. He is currently using rsync to backup his snapshots and is not worried about the present state of the filesystem - only the snapshots. He''s looking for something faster. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html