hwtable.c has multiple entries that set 'hardware_handler "1 alua"' explicitly. But the kernel has been auto-attaching the ALUA hwhandler to devices that support it since 4.3, the only prerequisite being that scsi_dh_alua is present at device probing time (kernel commits d95dbff2, d6a32b98). "retain_attached_hwhandler" is also hard-wired since 4.3. Thus if the above prerequisite is met, there's no point in setting 'hardware_handler "1 alua"'. We've recently seen problems with the explicit setting of the alua hwhandler in the hwtable; if we do this and the device fails ALUA for whatever reason, setting up the multipath map fails entirely. Therefore we have reasons to try and remove 'hardware_handler "1 alua"' from the hwtable. But it could cause regressions in some cases, e.g. for distributions that don't force-load scsi_dh_alua before device probing, or for kernels older than 4.3. Opinions, please. Martin -- Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107 SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
