On Thu, 1 Feb 2001, Gerhard den Hollander wrote:
> * Mitch Collinsworth <[EMAIL PROTECTED]> (Thu, Feb 01, 2001 at 09:31:52AM -0500)
>
> >> The avg dump rate is listed as 2M/s
> >> The avg tape rate is listed as 10M/s
> >> ...
> >> is there any way to speed up the dump process ?
>
> > If you take a closer look at the numbers you'll see these are actually
> > averages over the individual file systems' dump rates, without taking
> > into account amount of data dumped for each data point in the average.
> > Put more plainly, these numbers are really bogus.
Oh crap. Maybe I should look more closely before shooting my mouth off.
The numbers are clearly correct. I must have _assumed_ this was some
other problem that I used to know about but can no longer recall even
though I seem to remember the details. :-/ My apologies to you and
to whoever's work I wrongly maligned.
> > To really know how fast your dumps are going, look down the KB/s
> > column. Your numbers look pretty good to me. You've got better than
> > 1 MB/s on all your big dumps.
>
> True.
> The point is though that 2.3M/s (which Im getting at the 0 dump of the
> biggest one) translates to about 10G/hr, which means it takes 11 hours to
> dump the largest slice.
Wow, that's one big partition. You _could_ cut it up into smaller
partitions or use the GNU tar top level directory trick but you
probably have your reasons why those solutions won't work for you.
The next step seems to be to optimize the hardware. Is the holding
disk on the same SCSI controller as the filesystems being backed up
and if so are you using all the controller's bandwidth? Maybe another
controller and faster holding disks would help? Maybe putting the
110 GB filesystem on it's own controller?
-Mitch
