[ale] Linux GUI or CLI backup tool

Brian Pitts brian at polibyte.com
Fri Feb 18 00:06:04 EST 2011


On 02/16/2011 11:37 AM, JD wrote:
> In  my experience, rsync has trouble with large files - anything over 
> 4GB. This isn't a file system limitation (though it used to be many yrs 
> ago). Perhaps someone else here knows how to make it work better?

I use it with files up to a couple hundred gigabytes in size without a
problem. If you don't have enough disk space or your disk is slower than
your network, '--inplace' can help.

> Have you have verified file permissions on the source directories?
> 
> Have you tried skipping sshfs for the rsync command?

Using rsync over sshfs (or NFS, or CIFS, or anything else that makes
remote storage look like local storage) is a bad idea. When both paths
rsync is working with are local storage it always copies the entire
file. Thus if you have a 100GB file stored both on a local disk and on a
remote system accessed over sshfs, if you change one bit of the copy and
use rsync to propogate the change to the remote copy, it will

read 100GB of data on the local system
send 100GB of data over the network
write 100GB of data on the remote system

Ouch, When one path is rsync running on another system (whether started
via ssh or as a daemon), then it can have both systems read their local
data and only send the changes over the network. Thus it would

read 100GB of data on the local system
read 100GB of data on the remote system
send a few bytes of data over the network
write a few bytes of data on the remote system (assuming you used
'--inplace')

> $ rsync  -v -u -a --rsh=ssh   --links --stats --progress --recursive 
> /source/dir srvname:backups/dir/

There are some redundancies here. '-a' means '-rlptgoD', so you don't
need '--links' or '--recursive'. Also, ssh is default so you don't need
to specify '--rsh'.

-- 
All the best,
Brian Pitts


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