Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
> On Sat, Oct 18, 2008 at 09:18:33PM +0200, Petersen, Joerg wrote: > > Well, my experience is that 8.0.7 is the fastest DRDB... > > Later Versions just got slower! > > Try: no-disk-flushes > > and: no-md-flushes > > if you are using DRBD >= 8.0.13 > > Not completely same to 8.0.7 but near to it... > > to recommend a known buggy version for imagined performance reasons is > not particular HA. > > > Hi Lars, > > > > I did these: > > > > node1:/opt # hdparm -t /dev/drbd0 > > > > Do these tests make any sence? > > if you care for write performance, > why are you doing read benchmarks? These are the only benchmarks I know how to do on both DRBD and non-DRBD partitions without destroying data. I actually care for both read and write performance obviously, since users will be both reading and writing I guess (file and mailserver). What I just did is copying a 2.5 GB file to different locations. Mind you, the file is on the same harddrive (on /). These are the results: to ext3 filesystem on /dev/drbd0: 17MB/sec to /opt (on the same LVM VG as drbd0): 20 MB/sec to / (non LVM, non DRBD): 24 MB/sec So it seems there is a slight performance drop for DRBD, but the overall performance is not that good. What is striking though, is that a scp to the other node results in a performance of about 60 MB/sec. Is there any logical explanation for this? Is this because of my copy tests read and write to the same drive? Can this explain the drop from about 60 MB/sec to about 20 MB/sec? Thank you. Bart