On Tue, 2004-05-18 at 09:42, Bernd Schubert wrote: > Hello Chris, > > > > > As a comparison data point, could you please try 2.6.6-mm3? I realize > > you don't want to run this kernel in production, but it would tell us if > > I understand the problems at hand. > > the results in 2.6.6-mm3 are below, we almost consider to run this kernel > version. > > Here are two other interesting facts: > > 1.) During the filecreation in 2.4.26 the load on the system was around 3-4, > whereas in 2.6.6-mm3 the load was at about 8-9. > Which procs contributed to this load? The simple dd should have kept the load at one.
> 2.) When the dd file creation process finished (2.4.26 was running) the system > became so unresponsible, that the drdb connection timed out and a resync > process automatically started when the system became responsible again. I > don't have any comparism to 2.6.6-mm3 since we would need another drbd > version. Also, I don't know if this happend when dd finished or when > rm-started, since both were running from a script. > Probably the rm. [ 2.6.6-mm3 is much faster ] > Do you have any ideas how we could improve 2.4.x? > 2.6.6-mm has a few key improvements. There's less metadata fragmentation thanks to some block allocator fixes. More importantly, during the rm, metadata blocks are read in 16 at a time instead of 1 at a time. I'd be happy to give someone pointers on porting the metadata readahead bits back to 2.4. -chris
