Interesting speed benchmarks

[Robert Huff]

Peter Jeremy writes:

>  > >         $DUMP_LEVEL -D $DUMPDATES_FILE -Lau -f 
>  > > 
>  > >         gets me 2 +/- 0.2 mbytes/sec.
>  > >         Is this a reasonable value?  (I.e. is dump the limiting
>  > > factor?)  Do I need to reconfigure something, or is my hardware just
>  > > lame?
>  
>  I presume you are dumping an internal SCSI disk onto a USB disk.  Dump
>  is slow but shouldn't be that slow.  Doing a dump of root, I get
>  10MB/s on one system and 15MB/s on another.  Even my P-120 firewall
>  gets 2.7MB/s and it is actually CPU limited, not disk limited.  What
>  do you get if you do the dump to /dev/null?

huff@>>dump 0 -D /tmp/DF -Lau -f /dev/null /usr >& /tmp/null_dump
huff@>>cat /tmp/null_dump
  DUMP: Date of this level 0 dump: Mon Jan 29 10:26:38 2007
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping snapshot of /dev/da1s1d (/usr) to /dev/null
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 27192344 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: 0.75% done, finished in 11:01 at Mon Jan 29 21:33:18 2007
  DUMP: 3.10% done, finished in 5:12 at Mon Jan 29 15:49:28 2007
  DUMP: 5.74% done, finished in 4:06 at Mon Jan 29 14:48:31 2007

	etc.

  DUMP: 95.56% done, finished in 0:10 at Mon Jan 29 14:12:07 2007
  DUMP: 97.56% done, finished in 0:05 at Mon Jan 29 14:12:37 2007
  DUMP: 99.22% done, finished in 0:01 at Mon Jan 29 14:13:52 2007
  DUMP: 99.99% done, finished soon
  DUMP: DUMP: 27485576 tape blocks on 1 volume
  DUMP: finished in 13818 seconds, throughput 1989 KBytes/sec
  DUMP: level 0 dump on Mon Jan 29 10:26:38 2007
  DUMP: Closing /dev/null
  DUMP: DUMP IS DONE

	It would seem the USB connection is not the bottleneck.  :-)
	The last possibility would be a local misconfiguration that
limits the speed.  Ideas for what that might be are appreciated,
	But assuming it really is dump - what next?


					Robert Huff