[ILUG] Dump very slow across gigabit network

[Conor Daly]

On Fri, Sep 14, 2007 at 10:16:05AM +0100 or so it is rumoured hereabouts, 
Conor Daly thought:
> On Fri, Sep 14, 2007 at 08:31:03AM +0100 or so it is rumoured hereabouts, 
> Michael Watterson thought:
>  
> > How fast is the tape unit backup from the local disk?
> 
> 200Gb took just under 3.5 hours last night.  Dump reports:
> 
> DUMP: Volume 1 completed at: Fri Sep 14 05:21:16 2007
>   DUMP: Volume 1 208819200 blocks (203925.00MB)
>   DUMP: Volume 1 took 3:33:34
>   DUMP: Volume 1 transfer rate: 16296 kB/s
> 
> This is about 10 times the rate reported by dump on the source machine.
>  
> > How fast is the source machine copying to itself via loopback "localhost"?
> 
> Dunno yet, backup is still running.  Will check soon.

Ok, ran a 

dump -0 -f /path/to/local/file/on/disk /filesystem 

on both the tape host and on the client machine.  On the tape host:

  DUMP: Volume 1 10080050 blocks (9843.80MB)
  DUMP: Volume 1 took 0:04:54
  DUMP: Volume 1 transfer rate: 34285 kB/s



On the client machine:

  DUMP: Volume 1 14924940 blocks (14575.14MB)
  DUMP: Volume 1 took 0:32:28
  DUMP: Volume 1 transfer rate: 7661 kB/s

So, on the tape host, a dump to local disk is twice as fast as a dump to
tape.  However, on the client machine, a dump to local disk is only half
as fast as the dump to tape on the tape host.

Currently running a dump to remote disk from the client machine to the
tape host.  This is running at 1500kB/s.

A straight disk to disk copy of a 7Gb file on the client machine runs at
50000kB/s

A straight disk to disk copy of a 9Gb file on the tape host runs at
14000kB/s

Going to try a cpio test next...

Conor
-- 
Conor Daly <conor.daly at cod.homelinux.org>
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