On Wed, Mar 27, 2013 at 6:12 AM, Robinson, Eric <[email protected]> wrote: >> >> > In the simplest terms, we currently have resources: >> >> > >> >> > A = drbd >> >> > B = filesystem >> >> > C = cluster IP >> >> > D thru J = mysql instances. >> >> > >> >> > Resource group G1 consists of resources B through J, in >> >> that order, and is dependent on resource A. >> >> > >> >> > This fails over fine, but it has the serious disadvantage >> >> that if you stop or remove a mysql resource in the middle of the >> >> list, all of the ones after it stop too. For example, if >> you stop G, >> >> then H thru J stop as well. >> >> > >> >> > We want to change it so that the resource group G1 consists >> >> only of resources B & C. All of the mysql instances (D thru >> >> J) are individually dependent on group G1, but not >> dependent on each >> >> other. That way you can stop or remove a mysql resource without >> >> affecting the others. >> >> > >> >> > I saw this scenario described in the Pacemaker docs, but I >> >> cannot find an example of the syntax. >> >> >> >> You can use two resource-sets and go without groups, with that crm >> >> shell >> >> syntax: >> >> >> >> order o_drbd-filesystem-ip-dbs inf: A:promote B C (D E F G H I J) >> >> colocate co_all-follow-drbd inf: (D E F G H I J) B C A:Master >> >> >> >> Regards, >> >> Andreas >> >> >> > >> > Oh my gosh, that's what I have been trying to figure out >> for a year or more. I am very excited to try this. Note that >> I actually have more like 50 mysql resources, not just 7 like >> in the example. Will that be a problem? >> >> No. >> >> Did you also consider: >> >> G1 = A, B, C >> >> colocate D with G1 >> order D after G1 >> >> colocate E with G1 >> order E after G1 >> >> ... >> >> The set syntax cuts down on the duplication, but the above >> will also work. >> > > I tried that but without all the extra order statements. I thought the order > was implied. > > By definition, doesn't... > > colocation c1 inf: D G1 > > ..mean "figure out where to start G1 and THEN put D there?"
No. Not in the way you're thinking. "THEN" applies to the order in which decisions are made, once the decision is made the order in which they are executed is unrelated. _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
