[DRBD-user] Reducing loadavg / iowait? a few more questions

Bernd Schubert bernd.schubert at pci.uni-heidelberg.de
Wed Aug 3 16:18:36 CEST 2005

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Wednesday 03 August 2005 01:09, Rob Petri wrote:
> Three questions.
> Do you really see that large of a performance boost on 2.6?

Well, it must have been rather exactly a year ago when I posted our problems 
with 2.4. to the list. As far as I remember it got a rather larger discussion 
with Lars and I also posted benmark results with 2.4. If I would repeat those 
tests now, with 2.6.11, they would look much better.

> Does it apply to mode C as well?

Until we switched from 2.6. to 2.4. we always used protocol C, since it was 
sufficiently fast, so no need to bother with finetuning.

> Does anyone know why it is so much faster on 2.6?

The question rather would be, why was it so slow for us with 2.4.x, as 
drbd-0.6 + 2.4.x had about the same speed as drbd-0.7 + 2.6.x.

Well, there have been other reports to the list were drbd-0.7 + 2.4 got much 
more than 11-14MB/s, so I think its somehow related to our system, though 
nobody really understood whats going on.


Bernd Schubert
Physikalisch Chemisches Institut / Theoretische Chemie
Universität Heidelberg
INF 229
69120 Heidelberg
e-mail: bernd.schubert at pci.uni-heidelberg.de

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