Re: [cobalt-users] RaQ3/4 simultaneous file transfers (uploads)

["cbtrussell" <cbtrussell@xxxxxxxxxxx>]

> cbtrussell wrote:
>
> > The question: how can I know when I'm reaching the capacity of the RaQ
to
> > receive simultaneous uploads? I've got to think that some number of
RaQ's
> > running full tilt at 4am will eventually saturate the capacity of the
drive
> > to write all that data...anyone have any thoughts how to tell for sure?
>
> We do almost exactly the same.  I don't worry about saturating the
> server and so far I've seen no evidence of it.  However, we don't do it
> at 4am, that's when the system's already busy doing it's cron.daily
> jobs.  We backup the systems beginning at 1 am, and we start transfers
> at 2 am.  And we upload one system at a time.
>
> It's been a long time since I looked at linux internals, but I _believe_
> that the disk write mechanism does "elevator" caching... that is it
> writes first to memory, then to the right location on the drive when the
> head reaches it.  At least I don't hear head thrashing when doing
> multiple disk writes to a local system.

Thanks for the reply, Jeff. I may have to get away from the default
RaQbackup install script and start setting these up under crontab so they
run at pre-scheduled times, just as you are doing. Seems like the best way
to ensure everything runs smoothly. Is that how you do it, just staggering
the start times on each server's upload transfer session? Or do you 'pull'
the transfers from the target machine?

Brandon