Hi!
I just did some block device tuning according to some expert's advice which resulted in multipath failures. I'm not going to discuss this as I'll have to investigate further, but I'd like to point out that the messages like "[440682.559851] blk_rq_check_limits: over max size limit." lack the affected device!
It's quite hard to debug if you have more than 90 disks attached:
Aug 6 14:58:08 h06 multipathd: 65:240: mark as failed
Aug 6 14:58:08 h06 multipathd: SAP_T11_I03-E3: remaining active paths: 4
Aug 6 14:58:08 h06 multipathd: 68:48: mark as failed
Aug 6 14:58:08 h06 multipathd: SAP_T11_I03-E3: remaining active paths: 3
Aug 6 14:58:08 h06 multipathd: 8:208: mark as failed
Aug 6 14:58:08 h06 multipathd: SAP_T11_I03-E4: remaining active paths: 3
Aug 6 14:58:08 h06 multipathd: 67:80: mark as failed
Aug 6 14:58:08 h06 multipathd: SAP_T11_I03-E4: remaining active paths: 2
Aug 6 14:58:08 h06 kernel: [440682.559851] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.559891] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.559916] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.559928] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.559966] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.559996] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560016] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560037] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560058] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560106] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560149] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560176] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560189] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560223] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560257] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560277] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560296] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560319] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.560333] device-mapper: multipath: Failing path 65:240.
Aug 6 14:58:08 h06 kernel: [440682.560346] device-mapper: multipath: Failing path 68:48.
Aug 6 14:58:08 h06 kernel: [440682.560429] device-mapper: multipath: Failing path 67:80.
Aug 6 14:58:08 h06 kernel: [440682.560436] device-mapper: multipath: Failing path 8:208.
Aug 6 14:58:08 h06 kernel: [440682.561345] sd 2:0:0:7: alua: port group 01 state N non-preferred supports tolusNA
Aug 6 14:58:08 h06 kernel: [440682.561500] sd 3:0:2:7: alua: port group 01 state N non-preferred supports tolusNA
Aug 6 14:58:08 h06 kernel: [440682.562075] sd 2:0:4:7: alua: port group 01 state N non-preferred supports tolusNA
Aug 6 14:58:08 h06 kernel: [440682.562257] sd 3:0:4:7: alua: port group 01 state N non-preferred supports tolusNA
Aug 6 14:58:08 h06 kernel: [440682.562393] sd 3:0:8:7: alua: port group 01 state N non-preferred supports tolusNA
Aug 6 14:58:08 h06 kernel: [440682.676078] sd 3:0:2:7: alua: port group 01 switched to state A
Aug 6 14:58:08 h06 kernel: [440682.676091] sd 2:0:0:7: alua: port group 01 switched to state A
Aug 6 14:58:08 h06 kernel: [440682.676108] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.676112] blk_rq_check_limits: over max size limit.
Aug 6 14:58:08 h06 kernel: [440682.676115] blk_rq_check_limits: over max size limit.
Is this problem fixed in a newer kernel?
For the curious: I tuned queue/max_sectors_kb for the paths in a multipath device, but didn't tune the multipath device itself...
Regards,
Ulrich
P.S.: Plese keep CC: as I'm not subscribed to the list