Open Stack

On 29/10, Ignazio Cassano wrote:
> Hello,
> I created an openstack environment with two compute nodes.
> A this time only one virtual machine is running on compute-1, and
> multipath -ll shows :
> [root at compute-1 ansible]# multipath -ll
> mpatha (3600601602b7150006c829a5f26c92aa8) 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
> | |- 11:0:0:19 sdl 8:176 active ready running
> | `- 15:0:0:19 sdo 8:224 active ready running
> `-+- policy='round-robin 0' prio=10 status=enabled
>   |- 9:0:0:19  sdm 8:192 active ready running
>   `- 13:0:0:19 sdn 8:208 active ready running
>
> It's OK.
> Now I migrated the instance on another compute node and on the compute-1:
> [root at compute-1 ansible]# multipath -ll
> Oct 29 18:26:11 | sdl: alua not supported
> Oct 29 18:26:11 | sdo: alua not supported
> Oct 29 18:26:11 | sdm: alua not supported
> Oct 29 18:26:11 | sdn: alua not supported
> mpatha (3600601602b7150006c829a5f26c92aa8) 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=0 status=active
> | |- 11:0:0:19 sdl 8:176 active faulty running
> | `- 15:0:0:19 sdo 8:224 active faulty running
> `-+- policy='round-robin 0' prio=0 status=enabled
>   |- 9:0:0:19  sdm 8:192 active faulty running
>   `- 13:0:0:19 sdn 8:208 active faulty running
>
> It does not clean very well the multipath , are you agree ?
> I must clean it by hand using multipath -f and  echo 1 >
> /sys/block/$DEVICE/device/delete
> Does the work must be done by os-brick ?
> Ignazio
>
>

Hi,

It looks like it actually didn't get cleaned up at all.  :-(

This aligns with os-brick not finding the individual paths and saying
it's disconnecting from [].

There should be a Nova call to os-brick's disconnect_volume, please
check if the connection_information parameter passed to the
disconnect_volume is the same as what was passed to the connect_volume
for that same volume.

If it is the same information, then we'd have to look into why os-brick
is not being able to find the devices.

If the information is different, then this could be caused by Nova
making a second call to initialize_connection on the source host
thinking that the Cinder driver is idempotent. [1]

Could you check the exact Queens Nova version you are running?

Because I believe that specific Nova bug was fixed in 17.0.10 [2] and
not in the initial Queens release (17.0.0).

Cheers,
Gorka.

[1]: https://bugs.launchpad.net/nova/+bug/1754716
[2]: https://github.com/openstack/nova/commit/013f421bca4067bd430a9fac1e3b290cf1388ee4

>
>
> Il giorno gio 29 ott 2020 alle ore 09:12 Gorka Eguileor <geguileo at redhat.com>
> ha scritto:
>
> > On 28/10, Ignazio Cassano wrote:
> > > Hello Gorka, I would like to know if with unity iscsi driver,  I must
> > > configure iscsi initiator on both compute and controller nodes.
> > > At this time I installed and cinfigured iscsi initiator only on compute
> > > nodes and I got a lot of faulty devices when volumes ate detached.
> > > Thanks
> > > Ignazio
> > >
> >
> > Hi,
> >
> > Both compute and controller nodes are in the data path.  Computes when
> > instances use the volumes, and controllers when we create volume from
> > images, do generic volume migrations, create or restore backups, etc.
> >
> > Unless your deployment isn't doing any of the Cinder operations that
> > involve the data plane, you'll have to configure iSCSI on the controller
> > as well.
> >
> > Having said that, whether you configure the iSCSI initiator or not on
> > the controller will have no effect on the paths used by the compute.
> >
> > I've seen the iSCSI initiator going crazy when the iscsid and the
> > iscsiadm are from different versions.  I've seen this in containerized
> > environments.
> >
> > Faulty paths on multipathing is a tricky business, because there are
> > different checkers, some generic (readsector0, tur, directio) and some
> > vendor specific (emc_clarrion, hp_wd, rdac), and each one behaves in a
> > different way.
> >
> > If you have a multipath device with faulty paths, that you think should
> > not be faulty, you should look into what's going on with those paths:
> >
> > - Confirm that the device is still in the system under /dev/XYZ
> > - Confirm in your storage array's console/webconsole that the volume is
> >   still mapped on that target-portal to that host's iscsi initiator
> >   name.
> > - Confirm you can read the faulty devices with dd on the host
> > - Confirm that the WWN of the device is the same in all the paths (using
> >   /lib/udev/scsi_id)
> > - Finally look into what checker is multipath using for your device
> >   (sometimes checkers have bugs).
> >
> > Cheers,
> > Gorka.
> >
> >
> > >
> > > Il Mar 20 Ott 2020, 19:58 Gorka Eguileor <geguileo at redhat.com> ha
> > scritto:
> > >
> > > > On 20/10, Ignazio Cassano wrote:
> > > > > This is the entre log from when the migration started:
> > > > >
> > > > > http://paste.openstack.org/show/799199/
> > > > >
> > > > > Ignazio
> > > >
> > > > Hi,
> > > >
> > > > There are no os-brick calls in there. :-(
> > > >
> > > > You should look for the call to connect_volume that should have
> > > > something like:
> > > >
> > > >   ==> disconnect_volume: call "{'args':
> > > > (<os_brick.initiator.connectors.iscsi
> > > >
> > > > And the second parameter to that call is a dictionary where you can see
> > > > the target_lun, target_luns, target_portals, target_portal, target_iqn,
> > > > target_iqns...  This will allow us to check if we are actually
> > connected
> > > > to those targets-portals
> > > >
> > > > The third parameter should contain two things that are relevant, the
> > > > scsi_wwn and the path.  You can check if the path exists and if that
> > > > path actually has that wwn using /lib/udev/scsi_id --page 0x83
> > > > --whitelisted $path
> > > >
> > > > Those are the things I would check, because the only reason I can think
> > > > that os-brick is not disconnecting any volumes are that the connection
> > > > info is not right, or that the volume is no longer connected.
> > > >
> > > > Cheers,
> > > > Gorka.
> > > >
> > > > >
> > > > > Il giorno mar 20 ott 2020 alle ore 11:23 Gorka Eguileor <
> > > > geguileo at redhat.com>
> > > > > ha scritto:
> > > > >
> > > > > > On 20/10, Ignazio Cassano wrote:
> > > > > > > Hello Gorka,this is what happens on nova compute with debug
> > enabled,
> > > > > > when I
> > > > > > > migrate an instance with iscsi volumes ( note Disconnecting
> > from[]
> > > > should
> > > > > > > be the issue):
> > > > > > >
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > The disconnect from [] is the right clue, not necessarily the
> > issue.
> > > > > >
> > > > > > OS-Brick is saying that for the connection information that has
> > been
> > > > > > passed in the "disconnect_volume" call (which is not present in the
> > > > > > emailed logs) there are no volumes present in the system.
> > > > > >
> > > > > > You should check the connection info that Nova is passing to
> > > > > > disconnect_volume and confirm if that data is correct.  For example
> > > > > > checking if the path present in the connection info dictionary is
> > the
> > > > > > same as the one in the instance's XML dump, or if the LUN from the
> > > > > > connection info dict is actually present in the system.
> > > > > >
> > > > > > There are multiple reasons why Nova could be passing the wrong
> > > > > > connection info to os-brick.  The ones that come to mind are:
> > > > > >
> > > > > > - There was a failed migration at some point, and Nova didn't
> > rollback
> > > > > >   the connection info on the BDM table.
> > > > > > - Nova is calling multiple times initialize_connection on Cinder
> > for
> > > > the
> > > > > >   same host and the driver being used is not idempotent.
> > > > > >
> > > > > > Cheers,
> > > > > > Gorka.
> > > > > >
> > > > > > > stderr= _run_iscsiadm_bare
> > > > > > >
> > > > > >
> > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/connectors/iscsi.py:1122
> > > > > > > 2020-10-20 09:52:33.066 132171 DEBUG
> > > > os_brick.initiator.connectors.iscsi
> > > > > > > [-] iscsi session list stdout=tcp: [10] 10.138.209.48:3260,9
> > > > > > > iqn.1992-04.com.emc:cx.ckm00184400687.a3 (non-flash)
> > > > > > > tcp: [11] 10.138.215.17:3260,8
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.a2
> > > > > > > (non-flash)
> > > > > > > tcp: [12] 10.138.215.17:3260,8
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.a2
> > > > > > > (non-flash)
> > > > > > > tcp: [13] 10.138.215.18:3260,7
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.b2
> > > > > > > (non-flash)
> > > > > > > tcp: [14] 10.138.215.18:3260,7
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.b2
> > > > > > > (non-flash)
> > > > > > > tcp: [15] 10.138.209.47:3260,6
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.b3
> > > > > > > (non-flash)
> > > > > > > tcp: [16] 10.138.209.47:3260,6
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.b3
> > > > > > > (non-flash)
> > > > > > > tcp: [9] 10.138.209.48:3260,9
> > > > iqn.1992-04.com.emc:cx.ckm00184400687.a3
> > > > > > > (non-flash)
> > > > > > >  stderr= _run_iscsi_session
> > > > > > >
> > > > > >
> > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/connectors/iscsi.py:1111
> > > > > > > 2020-10-20 09:52:33.078 132171 DEBUG
> > > > os_brick.initiator.connectors.iscsi
> > > > > > > [-] Resulting device map defaultdict(<function <lambda> at
> > > > > > 0x7f4f1b1f7cf8>,
> > > > > > > {(u'10.138.215.17:3260',
> > > > u'iqn.1992-04.com.emc:cx.ckm00184400687.a2'):
> > > > > > > (set([]), set([u'sdg', u'sdi'])), (u'10.138.209.47:3260',
> > > > > > > u'iqn.1992-04.com.emc:cx.ckm00184400687.b3'): (set([]),
> > set([u'sdo',
> > > > > > > u'sdq'])), (u'10.138.209.48:3260',
> > > > > > > u'iqn.1992-04.com.emc:cx.ckm00184400687.a3'): (set([]),
> > set([u'sdd',
> > > > > > > u'sdb'])), (u'10.138.215.18:3260',
> > > > > > > u'iqn.1992-04.com.emc:cx.ckm00184400687.b2'): (set([]),
> > set([u'sdm',
> > > > > > > u'sdk']))}) _get_connection_devices
> > > > > > >
> > > > > >
> > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/connectors/iscsi.py:844
> > > > > > > 2020-10-20 09:52:33.078 132171 DEBUG
> > > > os_brick.initiator.connectors.iscsi
> > > > > > > [-] Disconnecting from: [] _disconnect_connection
> > > > > > >
> > > > > >
> > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/connectors/iscsi.py:1099
> > > > > > > 2020-10-20 09:52:33.079 132171 DEBUG oslo_concurrency.lockutils
> > [-]
> > > > Lock
> > > > > > > "connect_volume" released by
> > > > > > > "os_brick.initiator.connectors.iscsi.disconnect_volume" :: held
> > > > 1.058s
> > > > > > > inner
> > > > /usr/lib/python2.7/site-packages/oslo_concurrency/lockutils.py:339
> > > > > > > 2020-10-20 09:52:33.079 132171 DEBUG
> > > > os_brick.initiator.connectors.iscsi
> > > > > > > [-] <== disconnect_volume: return (1057ms) None
> > trace_logging_wrapper
> > > > > > > /usr/lib/python2.7/site-packages/os_brick/utils.py:170
> > > > > > > 2020-10-20 09:52:33.079 132171 DEBUG
> > nova.virt.libvirt.volume.iscsi
> > > > [-]
> > > > > > > [instance: 0c846f66-f194-40de-b31e-d53652570fa7] Disconnected
> > iSCSI
> > > > > > Volume
> > > > > > > disconnect_volume
> > > > > > >
> > /usr/lib/python2.7/site-packages/nova/virt/libvirt/volume/iscsi.py:78
> > > > > > > 2020-10-20 09:52:33.080 132171 DEBUG os_brick.utils [-] ==>
> > > > > > > get_connector_properties: call u"{'execute': None, 'my_ip':
> > > > > > > '10.138.208.178', 'enforce_multipath': True, 'host':
> > > > 'podiscsivc-kvm02',
> > > > > > > 'root_helper': 'sudo nova-rootwrap /etc/nova/rootwrap.conf',
> > > > 'multipath':
> > > > > > > True}" trace_logging_wrapper
> > > > > > > /usr/lib/python2.7/site-packages/os_brick/utils.py:146
> > > > > > > 2020-10-20 09:52:33.125 132171 DEBUG os_brick.initiator.linuxfc
> > [-]
> > > > No
> > > > > > > Fibre Channel support detected on system. get_fc_hbas
> > > > > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/linuxfc.py:157
> > > > > > > 2020-10-20 09:52:33.126 132171 DEBUG os_brick.initiator.linuxfc
> > [-]
> > > > No
> > > > > > > Fibre Channel support detected on system. get_fc_hbas
> > > > > > >
> > /usr/lib/python2.7/site-packages/os_brick/initiator/linuxfc.py:157
> > > > > > > 2020-10-20 09:52:33.145 132171 DEBUG os_brick.utils [-] <==
> > > > > > > get_connector_properties: return (61ms) {'initiator':
> > > > > > > u'iqn.1994-05.com.redhat:fbfdc37eed4c', 'ip': u'10.138.208.178',
> > > > 'system
> > > > > > > uuid': u'4C4C4544-0051-4E10-8057-B6C04F425932', 'platform':
> > > > u'x86_64',
> > > > > > > 'host': u'podiscsivc-kvm02', 'do_local_attach': False, 'os_type':
> > > > > > > u'linux2', 'multipath': True} trace_logging_wrapper
> > > > > > > /usr/lib/python2.7/site-packages/os_brick/utils.py:170
> > > > > > >
> > > > > > >
> > > > > > > Best regards
> > > > > > > Ignazio
> > > > > > >
> > > > > > > Il giorno gio 15 ott 2020 alle ore 10:57 Gorka Eguileor <
> > > > > > geguileo at redhat.com>
> > > > > > > ha scritto:
> > > > > > >
> > > > > > > > On 14/10, Ignazio Cassano wrote:
> > > > > > > > > Hello, thank you for the answer.
> > > > > > > > > I am using os-brick 2.3.8 but I got same issues on stein with
> > > > > > os.brick
> > > > > > > > 2.8
> > > > > > > > > For explain better the situation I send you the output of
> > > > multipath
> > > > > > -ll
> > > > > > > > on
> > > > > > > > > a compute node:
> > > > > > > > > root at podvc-kvm01 ansible]# multipath -ll
> > > > > > > > > Oct 14 18:50:01 | sdbg: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdbe: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdbd: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdbf: alua not supported
> > > > > > > > > 360060160f0d049007ab7275f743d0286 dm-11 DGC     ,VRAID
> > > > > > > > > size=30G features='1 retain_attached_hw_handler' hwhandler='1
> > > > alua'
> > > > > > wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=0 status=enabled
> > > > > > > > > | |- 15:0:0:71  sdbg 67:160 failed faulty running
> > > > > > > > > | `- 12:0:0:71  sdbe 67:128 failed faulty running
> > > > > > > > > `-+- policy='round-robin 0' prio=0 status=enabled
> > > > > > > > >   |- 11:0:0:71  sdbd 67:112 failed faulty running
> > > > > > > > >   `- 13:0:0:71  sdbf 67:144 failed faulty running
> > > > > > > > > 360060160f0d049004cdb615f52343fdb dm-8 DGC     ,VRAID
> > > > > > > > > size=80G features='2 queue_if_no_path
> > retain_attached_hw_handler'
> > > > > > > > > hwhandler='1 alua' wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=50 status=active
> > > > > > > > > | |- 15:0:0:210 sdau 66:224 active ready running
> > > > > > > > > | `- 12:0:0:210 sdas 66:192 active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 11:0:0:210 sdar 66:176 active ready running
> > > > > > > > >   `- 13:0:0:210 sdat 66:208 active ready running
> > > > > > > > > 360060160f0d0490034aa645fe52265eb dm-12 DGC     ,VRAID
> > > > > > > > > size=100G features='2 queue_if_no_path
> > > > retain_attached_hw_handler'
> > > > > > > > > hwhandler='1 alua' wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=50 status=active
> > > > > > > > > | |- 12:0:0:177 sdbi 67:192 active ready running
> > > > > > > > > | `- 15:0:0:177 sdbk 67:224 active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 11:0:0:177 sdbh 67:176 active ready running
> > > > > > > > >   `- 13:0:0:177 sdbj 67:208 active ready running
> > > > > > > > > 360060160f0d04900159f225fd6126db9 dm-6 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
> > > > > > > > > | |- 11:0:0:26  sdaf 65:240 active ready running
> > > > > > > > > | `- 13:0:0:26  sdah 66:16  active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 12:0:0:26  sdag 66:0   active ready running
> > > > > > > > >   `- 15:0:0:26  sdai 66:32  active ready running
> > > > > > > > > Oct 14 18:50:01 | sdba: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdbc: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdaz: alua not supported
> > > > > > > > > Oct 14 18:50:01 | sdbb: alua not supported
> > > > > > > > > 360060160f0d049007eb7275f93937511 dm-10 DGC     ,VRAID
> > > > > > > > > size=40G features='1 retain_attached_hw_handler' hwhandler='1
> > > > alua'
> > > > > > wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=0 status=enabled
> > > > > > > > > | |- 12:0:0:242 sdba 67:64  failed faulty running
> > > > > > > > > | `- 15:0:0:242 sdbc 67:96  failed faulty running
> > > > > > > > > `-+- policy='round-robin 0' prio=0 status=enabled
> > > > > > > > >   |- 11:0:0:242 sdaz 67:48  failed faulty running
> > > > > > > > >   `- 13:0:0:242 sdbb 67:80  failed faulty running
> > > > > > > > > 360060160f0d049003a567c5fb72201e8 dm-7 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
> > > > > > > > > | |- 12:0:0:57  sdbq 68:64  active ready running
> > > > > > > > > | `- 15:0:0:57  sdbs 68:96  active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 11:0:0:57  sdbp 68:48  active ready running
> > > > > > > > >   `- 13:0:0:57  sdbr 68:80  active ready running
> > > > > > > > > 360060160f0d04900c120625f802ea1fa dm-9 DGC     ,VRAID
> > > > > > > > > size=25G features='2 queue_if_no_path
> > retain_attached_hw_handler'
> > > > > > > > > hwhandler='1 alua' wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=50 status=active
> > > > > > > > > | |- 11:0:0:234 sdav 66:240 active ready running
> > > > > > > > > | `- 13:0:0:234 sdax 67:16  active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 15:0:0:234 sday 67:32  active ready running
> > > > > > > > >   `- 12:0:0:234 sdaw 67:0   active ready running
> > > > > > > > > 360060160f0d04900b8b0615fb14ef1bd dm-3 DGC     ,VRAID
> > > > > > > > > size=50G features='2 queue_if_no_path
> > retain_attached_hw_handler'
> > > > > > > > > hwhandler='1 alua' wp=rw
> > > > > > > > > |-+- policy='round-robin 0' prio=50 status=active
> > > > > > > > > | |- 11:0:0:11  sdan 66:112 active ready running
> > > > > > > > > | `- 13:0:0:11  sdap 66:144 active ready running
> > > > > > > > > `-+- policy='round-robin 0' prio=10 status=enabled
> > > > > > > > >   |- 12:0:0:11  sdao 66:128 active ready running
> > > > > > > > >   `- 15:0:0:11  sdaq 66:160 active ready running
> > > > > > > > >
> > > > > > > > > The active running are related to running virtual machines.
> > > > > > > > > The faulty are related to virtual macnines migrated on other
> > kvm
> > > > > > nodes.
> > > > > > > > > Every volume has 4 path because iscsi on unity needs two
> > > > different
> > > > > > vlans,
> > > > > > > > > each one with 2 addresses.
> > > > > > > > > I think this issue can be related to os-brick because when I
> > > > migrate
> > > > > > a
> > > > > > > > > virtual machine from host A host B in the cova compute log on
> > > > host A
> > > > > > I
> > > > > > > > read:
> > > > > > > > > 2020-10-13 10:31:02.769 118727 DEBUG
> > > > > > os_brick.initiator.connectors.iscsi
> > > > > > > > > [req-771ede8c-6e1b-4f3f-ad4a-1f6ed820a55c
> > > > > > > > 66adb965bef64eaaab2af93ade87e2ca
> > > > > > > > > 85cace94dcc7484c85ff9337eb1d0c4c - default default]
> > > > *Disconnecting
> > > > > > from:
> > > > > > > > []*
> > > > > > > > >
> > > > > > > > > Ignazio
> > > > > > > >
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > That's definitely the right clue!!  Though I don't fully agree
> > with
> > > > > > this
> > > > > > > > being an os-brick issue just yet.  ;-)
> > > > > > > >
> > > > > > > > Like I mentioned before, RCA is usually non-trivial, and
> > > > explaining how
> > > > > > > > to debug these issues over email is close to impossible, but if
> > > > this
> > > > > > > > were my system, and assuming you have tested normal
> > attach/detach
> > > > > > > > procedure and is working fine, this is what I would do:
> > > > > > > >
> > > > > > > > - Enable DEBUG logs on Nova compute node (I believe you already
> > > > have)
> > > > > > > > - Attach a new device to an instance on that node with --debug
> > to
> > > > get
> > > > > > > >   the request id
> > > > > > > > - Get the connection information dictionary that os-brick
> > receives
> > > > on
> > > > > > > >   the call to connect_volume for that request, and the data
> > that
> > > > > > > >   os-brick returns to Nova on that method call completion.
> > > > > > > > - Check if the returned data to Nova is a multipathed device or
> > > > not (in
> > > > > > > >   'path'), and whether we have the wwn or not (in
> > 'scsi_wwn').  It
> > > > > > > >   should be a multipath device, and then I would check its
> > status
> > > > in
> > > > > > the
> > > > > > > >   multipath daemon.
> > > > > > > > - Now do the live migration (with --debug to get the request
> > id)
> > > > and
> > > > > > see
> > > > > > > >   what information Nova passes in that request to os-brick's
> > > > > > > >   disconnect_volume.
> > > > > > > >   - Is it the same? Then it's likely an os-brick issue, and I
> > can
> > > > have
> > > > > > a
> > > > > > > >     look at the logs if you put the logs for that os-brick
> > detach
> > > > > > > >     process in a pastebin [1].
> > > > > > > >   - Is it different? Then it's either a Nova bug or a Cinder
> > driver
> > > > > > > >     specific bug.
> > > > > > > >     - Is there a call from Nova to Cinder, in the migration
> > > > request,
> > > > > > for
> > > > > > > >       that same volume to initialize_connection passing the
> > source
> > > > host
> > > > > > > >       connector info (info from the host that is currently
> > > > attached)?
> > > > > > > >       If there is a call, check if the returned data is
> > different
> > > > from
> > > > > > > >       the one we used to do the attach, if that's the case then
> > > > it's a
> > > > > > > >       Nova and Cinder driver bug that was solved on the Nova
> > side
> > > > in
> > > > > > > >       17.0.10 [2].
> > > > > > > >     - If there's no call to Cinder's initialize_connection, the
> > > > it's
> > > > > > > >       most likely a Nova bug. Try to find out if this
> > connection
> > > > info
> > > > > > > >       makes any sense for that host (LUN, target, etc.) or if
> > this
> > > > is
> > > > > > > >       the one from the destination volume.
> > > > > > > >
> > > > > > > > I hope this somehow helps.
> > > > > > > >
> > > > > > > > Cheers,
> > > > > > > > Gorka.
> > > > > > > >
> > > > > > > >
> > > > > > > > [1]: http://paste.openstack.org/
> > > > > > > > [2]: https://review.opendev.org/#/c/637827/
> > > > > > > >
> > > > > > > > >
> > > > > > > > > Il giorno mer 14 ott 2020 alle ore 13:41 Gorka Eguileor <
> > > > > > > > geguileo at redhat.com>
> > > > > > > > > ha scritto:
> > > > > > > > >
> > > > > > > > > > On 09/10, Ignazio Cassano wrote:
> > > > > > > > > > > Hello Stackers, I am using dell emc iscsi driver on my
> > > > centos 7
> > > > > > > > queens
> > > > > > > > > > > openstack. It works and instances work as well but on
> > compute
> > > > > > nodes I
> > > > > > > > > > got a
> > > > > > > > > > > lot a faulty device reported by multipath il comand.
> > > > > > > > > > > I do know why this happens, probably attacching and
> > detaching
> > > > > > > > volumes and
> > > > > > > > > > > live migrating instances do not close something well.
> > > > > > > > > > > I read this can cause serious performances problems on
> > > > compute
> > > > > > nodes.
> > > > > > > > > > > Please, any workaround and/or patch is suggested ?
> > > > > > > > > > > Regards
> > > > > > > > > > > Ignazio
> > > > > > > > > >
> > > > > > > > > > Hi,
> > > > > > > > > >
> > > > > > > > > > There are many, many, many things that could be happening
> > > > there,
> > > > > > and
> > > > > > > > > > it's not usually trivial doing the RCA, so the following
> > > > questions
> > > > > > are
> > > > > > > > > > just me hoping this is something "easy" to find out.
> > > > > > > > > >
> > > > > > > > > > What os-brick version from Queens are you running?  Latest
> > > > > > (2.3.9), or
> > > > > > > > > > maybe one older than 2.3.3?
> > > > > > > > > >
> > > > > > > > > > When you say you have faulty devices reported, are these
> > faulty
> > > > > > devices
> > > > > > > > > > alone in the multipath DM? Or do you have some faulty ones
> > with
> > > > > > some
> > > > > > > > > > that are ok?
> > > > > > > > > >
> > > > > > > > > > If there are some OK and some that aren't, are they
> > consecutive
> > > > > > > > devices?
> > > > > > > > > > (as in /dev/sda /dev/sdb etc).
> > > > > > > > > >
> > > > > > > > > > Cheers,
> > > > > > > > > > Gorka.
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> >
> >