Slow disk access while rsync - what should I tune?

[cronfy]

Hello.

Thanks again.

>    Yes, hardlinked backups pretty much destroy performance, mainly
>    because it destroys all locality of reference on the storage media
>    when files are slowly modified and get their own copies, mixed with
>    other 'old' files which have not been modified.  But theoretically
>    that should only effect the backup target storage and not the server's
>    production storage.

That is what surprised me when I did experiment with backups. If I
move backup off from the production server (to another less loaded
production server indeed), server that shuld be backed up starts to
run fine while backups are created. I think it means that problem is
not with vnode/dir caches..

At the other side the server who received backups became very slow. So
the problem looks to be related to writes or file creation/hardlinking
somehow...

At the moment I do not have server with ZFS, but I will think in this
direction. But I heard that ZFS has less performance than UFS, is it
really like this? I mean I have seen benchmarks and system
requirements, but would like to hear about your own experience.


-- 
// cronfy