rync killing the machine

[Warrick FitzGerald]

Hi All,

I have a production server that's running our corporate mail (Cyrus-IMAP).

I used to use cpio to archive the mail store, but that's just getting
silly now that there's about 40GB that it needs to run through.

I tried running rsync in order to backup the data, but as soon as I
started running the script the machine came to a grinding halt. I left
it running for about 30 minutes while rsync said it was analyzing the
file system but the server was un-usable and I was forced to kill it.

Is there some way to slow rsync down? I don’t mind if the initial sync
takes a day to run, I just dont want it to kill the machine.

I was given a suggestion to:

Use the -W flag to stop it comparing files byte for byte, don't use
checksums and add --progress so you can see what's happening.

Which seemed to help, but the machine is still pretty useless when rsync
runs.

Does anyone have any other ideas?

Thanks
Warrick