On Fri, Nov 20, 2009 at 01:57:15PM -0800, Chandra Seetharaman wrote: > Looks good to me except one comment below. > > On Fri, 2009-11-20 at 20:38 +0530, Chauhan, Vijay wrote: > > Hi, > > > > If READ_CAPACITY fails during device discovery, sd device gets attached > > with device size 0. Currently multipath discover these paths and adds > > into the map. RDAC patch checker sends inquiry on each path to check > > path status, which eventually marks this path as up. If this path is > > from owning controller then mode select will be issued to switch the > > pathgroup. But any I/O sent to this path(path with size 0) will eventually > > fail in sd_prep_fn due to incorrect device size and resulting to ping pong > > between pathgroups. We should only allow valid paths to get added in the > > map. Below patch checks two cases before adding paths; i.e.: > > 1) device size of path is not 0 > > 2) there is no mismatch between mpp size and new path size. > > > > Careful here. Some storage arrays (like the old HP MSA firmware) will report a size of zero for the inactive path. So we must make sure to not kill support for those. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N�g GF: Markus Rex, HRB 16746 (AG N�g) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
