Hello Everyone, I am testing stein with cinder iscsi driver for unity. Since I became crazy on queens, I decided to try with stein. At this time I have only one virtual machine with only one iscsi volume. It was running on podiscsivc-kvm02 and I migrated it on podiscsivc-kvm01. Let me show what multipath -ll displays on podiscsivc-kvm02 after live migration: 36006016006e04400dce5b45f0ac77301 dm-3 DGC ,VRAID size=40G features='1 retain_attached_hw_handler' hwhandler='1 alua' wp=rw |-+- policy='round-robin 0' prio=0 status=active | `- 17:0:0:60 sdm 8:192 failed faulty running `-+- policy='round-robin 0' prio=0 status=enabled |- 19:0:0:60 sdk 8:160 failed faulty running `- 21:0:0:60 sdj 8:144 failed faulty running And now on destination node podiscsivc-kvm01: 36006016006e04400dce5b45f0ac77301 dm-3 DGC ,VRAID size=40G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw |-+- policy='round-robin 0' prio=50 status=active | |- 17:0:0:14 sdm 8:192 active ready running | `- 15:0:0:14 sdl 8:176 active ready running `-+- policy='round-robin 0' prio=10 status=enabled |- 21:0:0:14 sdj 8:144 active ready running `- 19:0:0:14 sdk 8:160 active ready running On source node in /var/log/messages I get: Nov 18 10:34:19 podiscsivc-kvm02 multipathd: 36006016006e04400dce5b45f0ac77301: failed in domap for addition of new path sdl Nov 18 10:34:19 podiscsivc-kvm02 multipathd: 36006016006e04400dce5b45f0ac77301: uev_add_path sleep Nov 18 10:34:20 podiscsivc-kvm02 multipathd: 36006016006e04400dce5b45f0ac77301: failed in domap for addition of new path sdl Nov 18 10:34:20 podiscsivc-kvm02 kernel: device-mapper: table: 253:3: multipath: error getting device Nov 18 10:34:20 podiscsivc-kvm02 kernel: device-mapper: ioctl: error adding target to table Nov 18 10:34:20 podiscsivc-kvm02 multipathd: 36006016006e04400dce5b45f0ac77301: uev_add_path sleep On storage node seems it wotks fine, because the host access migrated from source to destination node. Multipath.conf is the following: blacklist { # Skip the files uner /dev that are definitely not FC/iSCSI devices # Different system may need different customization devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*" devnode "^hd[a-z][0-9]*" devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]" # Skip LUNZ device from VNX/Unity device { vendor "DGC" product "LUNZ" } } defaults { user_friendly_names no flush_on_last_del yes remove_retries 12 skip_kpartx yes } devices { # Device attributed for EMC CLARiiON and VNX/Unity series ALUA device { vendor "DGC" product ".*" product_blacklist "LUNZ" path_grouping_policy group_by_prio path_selector "round-robin 0" path_checker emc_clariion features "0" no_path_retry 12 hardware_handler "1 alua" prio alua failback immediate } } Why it leaves failed faulty running devices ? Is it a correct behaviour ? Every time I migrate my single instance from a node to another the number of files under /dev/disk/by-path increase of 4 (the number of path used for unity storage) on the destination node. I contacted Dell support and they said it is not an a problem of their cinder driver but ti could be related to nova. Please help me !!! I must decide if acquire nfs storage or iscsi storage. On the cinder compatibility drive matrix most vendors are iscsi.