On Fri, 27 Feb 2015, Bryn M. Reeves wrote: > On Thu, Feb 26, 2015 at 02:45:43PM -0500, Laurence Oberman wrote: > > For my particular use case its about providing the ability to warn on latencies being seen for multipath devices based on a given threshold. > > Of course this can simply be a userspace tool using what we already expose and do the calculations to make it work. > > When we have these latencies we then focus on which SAN path may or may not be contributing. > > Within multipathd we can already configure service time as a load balancer, perhaps we can do the monitoring in the same place. > > i.e. warn on service time above a threshold. > > One limitation here is that the dm-mpath target is request-based. > Currently dm-statistics are only available for bio-based targets. This > means that to obtain fine-grained stats for multipath devices we need to > insert a linear layer on top of the dm-mpath device. Someone could hack dm statistics to work on request based targets. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
