On Jul 27, 2009, at 4:09 PM, Coert Waagmeester <lgroups at waagmeester.co.za > wrote: > > On Mon, 2009-07-27 at 12:37 +0200, Coert Waagmeester wrote: >> On Mon, 2009-07-27 at 12:02 +0200, Alexander Dalloz wrote: >>>> >>>> On Mon, 2009-07-27 at 08:30 +0200, Coert Waagmeester wrote: >>> >>>>> Hello Roman, >>>>> >>>>> I am running drbd 8.2.6 (the standard centos version) >>> >>> >>> have you considered to test the drbd-8.3 packages? >>> >>> http://bugs.centos.org/view.php?id=3598 >>> >>> http://dev.centos.org/centos/5/testing/{i386,x86_64}/RPMS/ >>> >> >> Thank you very much for this tip! It was one very obvious place >> where I >> did not look yet. >> >> >> Would it be necessary to still recompile it for the TCP_NODELAY and >> such? >> >> I am just making sure, because >> http://www.nabble.com/Huge-latency-issue-with-8.2.6-td18947965.html >> makes it seem unnecessary. >> >> Why do the repositories provide both DRBD 8.0.x and 8.2.6? >> > > Here is a status update.... > _______________________________________________________________________________ > on both hosts I now run from the testing repository: > # rpm -qa | grep drbd > drbd83-8.3.1-5.el5.centos > kmod-drbd83-xen-8.3.1-4.el5.centos > _______________________________________________________________________________ > Here is my config (slightly condensed): > ----------------------------------------------------- > global { > usage-count yes; > } > common { > protocol C; > syncer { rate 50M; } > net { > # allow-two-primaries; } > sndbuf-size 0; } > # disk {no-disk-flushes; > # no-md-flushes; } > startup { wfc-timeout 0 ; } > } > resource xenfilesrv { > device /dev/drbd1; > disk /dev/vg0/xenfilesrv; > meta-disk internal; > > on baldur.mydomain.local { > address 10.99.99.1:7788; > } > on thor.mydomain.local { > address 10.99.99.2:7788; > } > } > resource xenfilesrvdata { > device /dev/drbd2; > disk /dev/vg0/xenfilesrvdata; > meta-disk internal; > > on baldur.mydomain.local { > address 10.99.99.1:7789; > } > on thor.mydomain.local { > address 10.99.99.2:7789; > } > } > _______________________________________________________________________________ > > xenfilesrv is a xen domU > in this domU i ran a dd with oflag direct: > --------------------------------------------------------- > # dd if=/dev/zero of=1gig.file bs=1M count=1000 oflag=direct > 1000+0 records in > 1000+0 records out > 1048576000 bytes (1.0 GB) copied, 147.997 seconds, 7.1 MB/s > > Just before I ran the dd this popped up in the secondary hosts syslog: > ---------------------------------------------------------------------- > Jul 27 21:51:42 thor kernel: drbd2: Method to ensure write ordering: > flush > Jul 27 21:51:42 thor kernel: drbd1: Method to ensure write ordering: > flush > > > _______________________________________________________________________________ > > What more can I try? > > To be quite honest, I have no idea what to do with/ where to find the > TCP_NODELAY socket options...... Use drbd option to disable flush/sync, but understand that during a power failure or system crash data will not be consistent on disk and you will need to sync the storage from the other server. -Ross -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090727/90fbc9c4/attachment-0005.html>