Re: [Dump-users] dump performance

[Eros A. <er...@la...>]

Stelian Pop wrote:
> 
> Playing with the blocksize parameter (-b) can dramatically improve
> the transfer rate (since dump always writes data - to the remote or

I am wondering if there is something wrong with my systems (either local or
remote, although when I do a dump on the system that has the tape  and when a
dump to /dev/null I obtain the same figures as when I write through the net). 
I have:

dump  (-b default)
  DUMP: DUMP: 2569003 tape blocks on 1 volumes(s)
  DUMP: finished in 3595 seconds, throughput 714 KBytes/sec
  DUMP: Volume 1 completed at: Sun Feb 13 00:43:07 2000
  DUMP: Volume 1 took 1:00:00
  DUMP: Volume 1 transfer rate: 713 KB/s

dump  -b 32
  DUMP: DUMP: 2565411 tape blocks on 1 volumes(s)
  DUMP: finished in 5388 seconds, throughput 476 KBytes/sec
  DUMP: Volume 1 completed at: Sun Feb 13 18:22:40 2000
  DUMP: Volume 1 took 1:29:54
  DUMP: Volume 1 transfer rate: 475 KB/s
  DUMP: DUMP: Date of this level 0 dump: Sun Feb 13 16:52:17 2000
  DUMP: DUMP: Date this dump completed:  Sun Feb 13 18:22:40 2000
  DUMP: DUMP: Average transfer rate: 475 KB/s

dump  -b 64
  DUMP: DUMP: 2565670 tape blocks on 1 volumes(s)
  DUMP: finished in 5212 seconds, throughput 492 KBytes/sec
  DUMP: Volume 1 completed at: Sun Feb 13 19:50:42 2000
  DUMP: Volume 1 took 1:26:52
  DUMP: Volume 1 transfer rate: 492 KB/s

dump  -b 2
  DUMP: DUMP: 2565542 tape blocks on 1 volumes(s)
  DUMP: finished in 3064 seconds, throughput 837 KBytes/sec
  DUMP: Volume 1 completed at: Mon Feb 14 10:01:29 2000
  DUMP: Volume 1 took 0:51:04
  DUMP: Volume 1 transfer rate: 837 KB/s
-- 
Eros Albertazzi
CNR-LAMEL, Via P.Gobetti 101, 40129 Bologna, Italy  
Tel: (+39)-051-639 9179
Fax: (+39)-051-639 9216
E-mail: er...@la...