VERY frustrated with FreeBSD/UFS stability - please help or comment...

[Eric Anderson]

On 05/22/07 06:39, Dag-Erling Smørgrav wrote:
> Gore Jarold <gore_jarold at yahoo.com> writes:
>> Specifically, I have private departmental fileservers that other
>> fileservers rsync to using Mike Rubel-style rsync snapshots:
>>
>> http://www.mikerubel.org/computers/rsync_snapshots/
>>
>> This means that the remote system runs a script like this:
>>
>> ssh user at host rm -rf backup.2
>> ssh user at host mv backup.1 backup.2
>> ssh user at host cp -al backup.0 backup.1
>> rsync /files user at host:/backup.0
> 
> This is extremely inefficient, as you have discovered.
> 
> Speaking in the abstract, what you want to do every day is the
> following:
> 
> client1% rsync --archive --delete /vol server:/backup/client1
> client2% rsync --archive --delete /vol server:/backup/client2
> server% for vol in /backup/* ; do mksnap_ffs $vol $vol/.snap/`date` ; done
> 
> No copying or deleting; you take a snapshot when the rsync job is done,
> and the next day you rsync again to the same directory; only what has
> actually changed will be transferred, and there is no need to create and
> populate full copies of each directory tree every time.


That's good for small file systems, but if you have a multi-terabyte 
file system, you're not going to be too happy about those results.  The 
snapshot will take a *very* long time, on a nearly full file system.


Eric