On 10/11/2016 08:22 AM, Hannes Reinecke wrote: > Autodetection will only work if the hardware handler is loaded. > If the handler is _not_ loaded autodetection won't work, either. > And if we add this patch multipath will never load the modules, neither. > So we need this functionality as a fallback if autodetect does not work. I'm pretty sure all works flawlessly with this patch. Because I use similar options for EMC VNX7500(CLARiiON) configured as ALUA "Failover Mode 4 (Asymmetric Active/Active)", with SLES-11/12 and RHEL-6 booting from SAN. For SLES it was added to DGC config: retain_attached_hw_handler yes detect_prio yes In RHEL it's included by default: http://pkgs.fedoraproject.org/cgit/rpms/device-mapper-multipath.git/plain/0117-RHBZ-1198424-autodetect-clariion-alua.patch And the modules are preloaded by multipathd/multipathd.service: ExecStartPre=/sbin/modprobe -a scsi_dh_alua scsi_dh_emc scsi_dh_rdac dm-multipath RDAC devices also depend *exclusively* on "retain_attached_hw_handler" and "detect_prio" to run in ALUA mode. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
