Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Mon, Oct 20, 2008 at 4:23 PM, Florian Haas <florian.haas at linbit.com> wrote: > Little, Kevin wrote: >> I searched the archives for this, but found nothing. > > Well if you search _this_ list's archives, that's not exactly suprising > as what you are after is more of a Heartbeat issue than a DRBD one. > Searching the linux-ha archives is likely to yield better results. > >> I've seen mentioned >> (http://fghaas.wordpress.com/2007/06/26/when-not-to-use-drbd/) that the >> fail-over time for DRBD+Heartbeat is on the order of 20 seconds. > > Well it's configurable (via the deadtime config entry in > /etc/ha.d/ha.cf), but on the order of between 15 to 30 seconds is what > people usually pick. We use the following settings: keepalive 75ms deadtime 300ms warntime 200ms Which seems to work ok. The link between the two nodes is a 10GE direct connection, so there shouldn't be any issues with the network delaying packets. When I first configured this, I kept an eye out for the 'warntime' messages in the logs for a week or so, and didn't see any. Our application is just iscsi exporting LVM luns from the drbd volumes, so there's no issue with recovery time - failover of the entire stack (ip, drbd, lvm, iscsi) is at most two seconds. I've tested it, and I'm able to play video off the iscsi volume, hard-reset the primary node, and have the video continue playing after a 5-odd second pause (presumably as the iscsi times out and retries). -Patrick -- http://www.labyrinthdata.net.au - WA Backup, Web and VPS Hosting