[SOLVED] Quick Rsync Question, Recursion.

BashTin · 05-21-2015, 05:34 PM

Hello,

have experimented with rsync a long time ago and have just returned to it for backups. It occurred to me that it is possible, unless rsync is 'smart' somehow, to recursively copy it's own backup.

I mean for instance if I want to backup the whole drive, sda1, to say sdb1 and I have a mount point for the backup such as /mnt/sda_sdb_backup. When the rsync gets to the /mnt/sda_sdb_backup dir would it just recursively copy itself to sdb1??? So on sdb you would end up with two copies, one on / (root) and one on /mnt (if it was big enough, or you would end up filling the drive and rsync would exit with an error). Or is rsync smarter than that? Last time I seem to recall adding /mnt to the exclude list.

Thanks, BashTin.

mralk3 · 05-21-2015, 05:46 PM

Rsync has an exclude option where you enter directory or file names and it skips those areas of your hard drive:

rsync man page:

Quote:

--exclude=PATTERN exclude files matching PATTERN

The first search result I found on duckduckgo.com for "exclude directory rsync backup" was:

http://articles.slicehost.com/2007/1...es-and-folders

Hope that helps.

BashTin · 05-21-2015, 06:00 PM

Quote:

Originally Posted by mralk3

Rsync has an exclude option where you enter directory or file names and it skips those areas of your hard drive:

rsync man page:

The first search result I found on duckduckgo.com for "exclude directory rsync backup" was:

http://articles.slicehost.com/2007/1...es-and-folders

Hope that helps.

Thank you, I know that

Quote:

Last time I seem to recall adding /mnt to the exclude list.

What I guess I mean is is the exclude necessary or is rsync smart enough to know it is copying it's own backup?

mralk3 · 05-21-2015, 06:04 PM

As far as I know you need to exclude and rsync is not smart enough to do that automatically. Everything I have found by searching the web points to rsync not having that functionality.

jailbait · 05-21-2015, 06:19 PM

Quote:

Originally Posted by BashTin

Thank you, I know that

What I guess I mean is is the exclude necessary or is rsync smart enough to know it is copying it's own backup?

rsync does not know when it is in a recursion loop. You have to exclude the backup directory from the rsync backup.

--------------------
Steve Stites

aaazen · 05-21-2015, 11:45 PM

Quote:

Originally Posted by BashTin

Hello,

have experimented with rsync a long time ago and have just returned to it for backups. It occurred to me that it is possible, unless rsync is 'smart' somehow, to recursively copy it's own backup.

I mean for instance if I want to backup the whole drive, sda1, to say sdb1 and I have a mount point for the backup such as /mnt/sda_sdb_backup. When the rsync gets to the /mnt/sda_sdb_backup dir would it just recursively copy itself to sdb1??? So on sdb you would end up with two copies, one on / (root) and one on /mnt (if it was big enough, or you would end up filling the drive and rsync would exit with an error). Or is rsync smarter than that? Last time I seem to recall adding /mnt to the exclude list.

Thanks, BashTin.

Besides using the '--exclude=/mnt/*' option there is also the 'x' option which limits the rsync source to a single file system.

Here is an example of copying the root file system to a file system mounted on /a14:

Code:

#cd /
#/usr/bin/rsync -axHAX --delete --numeric-ids \
           '--exclude=/lost+found/' \
           '--exclude=/proc/*' '--exclude=/sys/*' \
           '--exclude=/tmp/*'  '--exclude=/var/tmp/*' . /a14

BashTin · 05-22-2015, 06:30 AM

Thanks for the replies. Just wanted it clarified with people who are more knowledgeable.

comet.berkeley thanks for that. Will look into the x option as I don't want it copying the /boot partition over either, it might just be what is needed. /boot is in my exclude list but this is an interesting alternative.

BashTin.