[PLUG] rsync options for backup

[Galen Seitz]

On 06/21/2018 09:01 AM, Russell Senior wrote:
> The one possible downside of hardlinks I have run into in the past decade
> is if one or the other side is memory constrained. It requires tracking
> inode numbers to make links to files that have been seen already. If it
> causes trouble, get more memory. Hardlinks are worth it! :-)

In the context of my rsnapshot backups, I'm interested in whether it is 
worthwhile to try to preserve any hardlinks that exist within the 
filesystem that is being backed up.  The backups of the backups already 
use hardlinks to preserve disk space.  rsnapshot uses cp -al for this.

Here's an outline of how rsnapshot is doing the work.

On the machine containing a filesystem to be backed up, rsync is run to 
create a synced copy of the filesystem:
/usr/bin/rsync -avx --stats --delete --numeric-ids --relative 
--delete-excluded /boot/ /backups/rsnapshot/.sync/toto/

On the machine that holds the backups:
/usr/bin/rsync -avx --stats --delete --numeric-ids --relative 
--delete-excluded --rsh=/usr/bin/ssh toto-rsnapshot:/ 
/backups/rsnapshot/.sync/toto/
mv /backups/rsnapshot/daily.7/ /backups/rsnapshot/_delete.28957/
mv /backups/rsnapshot/daily.6/ /backups/rsnapshot/daily.7/
mv /backups/rsnapshot/daily.5/ /backups/rsnapshot/daily.6/
mv /backups/rsnapshot/daily.4/ /backups/rsnapshot/daily.5/
mv /backups/rsnapshot/daily.3/ /backups/rsnapshot/daily.4/
mv /backups/rsnapshot/daily.2/ /backups/rsnapshot/daily.3/
mv /backups/rsnapshot/daily.1/ /backups/rsnapshot/daily.2/
mv /backups/rsnapshot/daily.0/ /backups/rsnapshot/daily.1/
/bin/cp -al /backups/rsnapshot/.sync /backups/rsnapshot/daily.0
/bin/rm -rf /backups/rsnapshot/_delete.28957


galen
-- 
Galen Seitz
galens at seitzassoc.com