[ovirt-users] Re: Multipath flapping with SAS via FCP

Hi, I have some troubles with multipath. When I add SAS disk over FCP as Storage Domain via oVirt WebUI, The first link as active, but the second is stuck as failed. Volum disk is provided from Dell Compellent via FCP, and disk is transported in SAS. multipath is flapping in all hypervisor from the same domain disk: [root@isildur-adm ~]# tail -f /var/log/messages Feb 25 11:48:21 isildur-adm kernel: device-mapper: multipath: 253:3: Failing path 8:32. Feb 25 11:48:24 isildur-adm multipathd[659460]: 36000d31003d5c2000000000000000010: sdc - tur checker reports path is up Feb 25 11:48:24 isildur-adm multipathd[659460]: 8:32: reinstated Feb 25 11:48:24 isildur-adm multipathd[659460]: 36000d31003d5c2000000000000000010: remaining active paths: 2 Feb 25 11:48:24 isildur-adm kernel: device-mapper: multipath: 253:3: Reinstating path 8:32. Feb 25 11:48:24 isildur-adm kernel: sd 1:0:1:2: alua: port group f01c state S non-preferred supports toluSNA Feb 25 11:48:24 isildur-adm kernel: sd 1:0:1:2: alua: port group f01c state S non-preferred supports toluSNA Feb 25 11:48:24 isildur-adm kernel: device-mapper: multipath: 253:3: Failing path 8:32.

Feb 25 11:48:25 isildur-adm multipathd[659460]: sdc: mark as failed Feb 25 11:48:25 isildur-adm multipathd[659460]: 36000d31003d5c2000000000000000010: remaining active paths: 1 --- [root@isildur-adm ~]# multipath -ll 36000d31003d5c2000000000000000010 dm-3 COMPELNT,Compellent Vol size=1.5T features='1 queue_if_no_path' hwhandler='1 alua' wp=rw `-+- policy='service-time 0' prio=25 status=active |- 1:0:0:2 sdb 8:16 active ready running `- 1:0:1:2 sdc 8:32 failed ready running --- VDSM generate multipath.conf like this ( I have remove commented lines for read confort ) : [root@isildur-adm ~]# cat /etc/multipath.conf # VDSM REVISION 2.0 # This file is managed by vdsm. defaults { polling_interval 5 no_path_retry 16 user_friendly_names no flush_on_last_del yes fast_io_fail_tmo 5 dev_loss_tmo 30 max_fds 4096 } blacklist { protocol "(scsi:adt|scsi:sbp)" } no_path_retry 16 } Have you some idea why this link is flapping on my two hypervisor?