On Nov 20, 2007 8:32 AM, Tore Anderson <tore@xxxxxxxxx> wrote: > > > Re: default_path_grouping_policy in multipath.conf > > > > failover = 1 path per priority group > > multibus = all valid paths in 1 priority group > > > > Does this mean that if I'm using failover I'm not going to get > > multiple path throughput? And, on the flip side, if I'm sending data > > through multiple paths I'm not going to get failover support? > > Correct, and incorrect. With "failover" topology only one path will be > used at a time. With "multibus" all of them will be - but failing paths > _will not_ be used. So if you have eight paths to your storage and are > using multibus topology, load will be balanced over all eight paths. If > one fails, load will be balanced over the remaining seven. And if you > fix the failed path I/O will be balanced over all eight again. > > There's also the group_by_prio or group_by_serial topologies which is > normally used in setups with an active/passive controller pair (most > midrange gear are built in this way). In this case I/O is load balanced > over all the paths to the primary controller of a volume only, while the > remaining paths (usually to a standby controller) will only be used if > all (or enough) of the primary paths fail. > Hey Tore, I tested a 'multibus' config and it performs just as I'm hoping! :) Thanks! Scott -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
