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 04 October 2006 19:30, Lars Ellenberg wrote: > / 2006-10-04 18:36:40 +0200 > > \ Peter Sabaini: > > > > # hdparm -t /dev/cciss/c0d0 > > > > > > > > /dev/cciss/c0d0: > > > > Timing buffered disk reads: 208 MB in 3.03 seconds = 68.69 MB/sec > > > > > > > > It could be better, but its reasonable I think? > > well, actually, write performance would be more interesting. > make sure that the raid is not rebuilding at the same time. > > also, the cciss controler likes high values for > max-buffers > max-epoch-size > unplug-watermark Ok, that helped -- I now get around 23MB/s which is not great but a lot better than before :-) For the record I now use sndbuf-size 1M; max-buffers 32768; max-epoch-size 16384; unplug-watermark 32768; I cant test right now but from an earlier naive test (dd if=/dev/zero of=zero.dat bs=1M count=4096) write performance was around 32MB/s for the disk device (ext3 on top of lvm), so thats the limiting factor now I guess. Any advice on getting more out of that cciss? :-) Thanks a lot, peter. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Peter Sabaini ARC Seibersdorf research GmbH Biomedical Engineering / eHealth systems Reininghausstrasse 13/1, 8020 Graz, Austria T: +43(0)316 586570-55, F:+43(0)316 586570-12 peter.sabaini at arcsmed.at, http://www.arcsmed.at/ehs