Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
/ 2005-08-24 20:01:58 +0100 \ paddy: > > > Sorry, I missed the bit earlier about having multiple secondaries in drbd. > > > > > > As you know, I had assumed that this is not possible with 0.7, but I don't > > > recall exactly why. > > > > in short, because reliable multicast is tricky. > > I have only heard of it. > > Do you get all the magic out of the networking or do you have to do > more work in drbd itself ? to my knowledge, there currently is no (at least no open source) implementation of such a thing that would be usable by drbd. yes, we pretty much would have to (re)invent it ourselves. > > we have paying customers where we do a "tripple legged, two secondary" setup, > > but that is currently no so much for availability than for desaster recovery > > backup purposes. > > Cool! > What happens at fail-over ? are they primary/secondary/tertiary ? buy it, and I'll tell you :-> well, basically, in case they'd need the "tertiary", what would happen is, they phone us, and we do the tricky bit. *g* as I said, the "tertiary" is for desaster recovery, not for "high" availability, so in case it is needed, there already has been a desaster, and the additional latency of getting us involved is ok compared to everything else. you really do not want to have automatic failover to a distant data center just because heartbeat feels like it... cheers, -- : Lars Ellenberg Tel +43-1-8178292-0 : : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : : Schoenbrunner Str. 244, A-1120 Vienna/Europe http://www.linbit.com : __ please use the "List-Reply" function of your email client.