Re: Backup Command

On Tuesday, January 11, 2011 15:33:38 Ivan Lab=C3=A1th wrote:

On 01/11/11 15:19, Hubert Kario wrote:

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On Tuesday, January 11, 2011 14:54:38 Ivan Lab=C3=A1th wrote:

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On 01/10/11 14:36, Hubert Kario wrote:

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On Monday 10 of January 2011 14:25:32 Carl Cook wrote:

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Here is my proposed cron:
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btrfs subvolume snapshot hex:///home
/media/backups/snapshots/hex-{DATE}
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rsync --archive --hard-links --delete-during --delete-excluded
--inplace --numeric-ids -e ssh
--exclude-from=3D/media/backups/exclude-hex hex:///home
/media/backups/hex
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btrfs subvolume snapshot droog:///home
/media/backups/snapshots/droog-{DATE}
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rsync --archive --hard-links --delete-during --delete-excluded
--inplace --numeric-ids -e ssh
--exclude-from=3D/media/backups/exclude-droog droog:///home
/media/backups/droog
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Comments?  Criticisms?

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This will make the dates associated with snapshots offset by how =

often

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cron is run.
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In other words, if you run above script daily you will have data =

from

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2011.01.01 in the hex-2011.01.02 directory.
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I do save the current date, do a LVM snapshot on the source, rsyn=

c

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--inplace data over and do a local snapshot naming the folder usi=

ng the

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saved date. This way the date in the name of backup directory is =

exact

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to about a second.

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If you are mounting a LVM snapshot of an already mounted filesyste=

m,

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would you be willing verify that it is really a snapshot that is
mounted?
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e.g. touch /mnt/live/its_alive && ls /mnt/snapshot/
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I am nearly willing to bet it is not a snapshot.

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well, by "LVM snapshot on the source" I meant:
1. do lvcreate --snapshot
2. mount newly created volume
3. use the new directory as the base for rsync
4. arrange umount and destruction of the snapshot after rsync compl=

etes

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(no matter if it was successful)
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and this will in fact not make the "its_alive" visible in /mnt/snap=

shot

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You have to use this procedure if you use LVM snapshots for backup =

no

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matter to where do you copy data. That's why I shortened it to a si=

ngle

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point -- it's not the part that is important from btrfs perspective=

=2E

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Regards.

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The point I was trying to make is: it does not work with btrfs.
Try the above with a btrfs and you will be surprised.
If the source volume uses another filesystem, it should work properly=

=2E

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regards,
ivan

Yes, you are right, but I don't see a point in using LVM snapshots with=
 btrfs,=20
after all the ability to snapshot it on fs level is one of its defining=
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features...

--=20
Hubert Kario
QBS - Quality Business Software
02-656 Warszawa, ul. Ksawer=C3=B3w 30/85
tel. +48 (22) 646-61-51, 646-74-24
www.qbs.com.pl
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