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, Aug 09, 2008 at 11:44:25AM -0700, Casey Allen Shobe wrote: > On Aug 9, 2008, at 11:21 AM, Casey Allen Shobe wrote: > > * Maybe JFS is a bad choice to use on top of DRBD (kind of doubt it) and we > should use another filesystem who's disk accesses match DRBD's expectations > better. > > > After sending this E-mail, I decided to mkfs.ext3 the partition (with DRBD > slave connected). It got to the "writing inode tables" part, shot up to 1200 > pretty fast and then stuck. It's now been CRAWLING along at a snail's pace for > a good 10 minutes now, and is not yet up to 2000 (out of 5465, so I expect it > will be the better part of an hour or more before it completes, which seems > absolutely absurd for an mkfs). Additionally, I tried disconnecting the slave > midway through and speed did not improve. > > So the problem seems lower-level than the filesystem (just wanted to rule that > out). > > It also seems, since performance is terrible even when the slave is > disconnected, that the network is not a factor. > > The mkfs alone is pushing the server load up to 3.0, however the CPU > utilization is sticking at 0%, so CPU does not seem to be a factor either. familiarize yourself with the concept of the DRBD activity log. the config parameter would be "al-extents". verify that your disk subsystem has a non-volatile write cache enabled. then add to DRBDs configuration no-disk-flushes and no-md-flushes. see if that helps. -- : Lars Ellenberg http://www.linbit.com : : DRBD/HA support and consulting sales at linbit.com : : LINBIT Information Technologies GmbH Tel +43-1-8178292-0 : : Vivenotgasse 48, A-1120 Vienna/Europe Fax +43-1-8178292-82 : __ please don't Cc me, but send to list -- I'm subscribed