Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 10/14/2008 11:17 PM, Lars Marowsky-Bree wrote: > On 2008-10-14T18:32:50, Bart Coninckx <bart.coninckx at telenet.be> wrote: > >> Hi all, >> >> I previously posted about a sync going somewhat slow (managed to get it up to >> 18MB/sec). >> I figured this could be just the syncing, so I decided to do some performance >> tests as mentionned in the webinar. >> >> I used: >> dd if=/dev/zero of=/dev/drbd0 bs=1G count=1 oflag=direct > > oflag=direct uses direct sync'ing (obviously), which means there's not > very much optimization going on. bs=1G also means that a huge memory > block is allocated and flushed. > > So at least these parameters are far from sane - bs=16384 oflag=fsync > might provide better performance. Lars, the very point of this micro benchmark is to hammer the DRBD device _without_ any optimization, and compare the results of that to those produced on the lower level block device. Just my 2 cents. Florian -- : Florian G. Haas : LINBIT Information Technologies GmbH : Vivenotgasse 48, A-1120 Vienna, Austria When replying, there is no need to CC my personal address. I monitor the list on a daily basis. Thank you. LINBIT® and DRBD® are registered trademarks of LINBIT.