Erez Zilber [erezz@xxxxxxxxxxxx] wrote: > I understand. I've tried disktest, and it work ok. I have another > question - I'm running a single iSCSI initiator against 2 iSCSI > target. I started disktest on /dev/dm-1 and after a few seconds, I > disconnected the primary target. It took ~2 minutes until it failed > over to the secondary device. During these ~2 minutes, it seemed that > disktest is still reading data from the target, just slower. That's > very strange. After failover was completed, I was able to use the > secondary device. You said, "it seemed that disktest is still reading data from the target". Maybe it is reading some cached data (read-ahead or some other such thing...) Also, the multipath kernel module would not know that you have disconnected the target until an I/O fails. Depending on your error injection and the susystems design, the I/O failure could be as a result of a timeout (this depends on your/distro setting, generally 1 minute). > I have 2 questions: > > 1. > Which parameter in multipath.conf do I need to change > in order to failover in a few seconds? Is it polling_interval? I saw > that the default value is 5 seconds, which should be ok. Not an expert, but polling interval can't change the failover time. It may change the 'failback' time though! > 2. Before multipath decided that it needs to failover, why did I > see that traffic is still running? It had no device to work with at > that time. Depends on 'how you saw the traffic'! Could be false alarm. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
