On Tue, Feb 21, 2017 at 6:12 PM, Adam Litke <alitke@redhat.com> wrote:

On Tue, Feb 21, 2017 at 10:19 AM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:

...

Hello, currently I have a cluster of 3 hosts where each one has FC SAN connectivity to 4 LUNs: 3 are already configured as storage domains (1TB, 2TB, 4TB), one is free, not allocated. See here for screenshot:

https://drive.google.com/file/d/0BwoPbcrMv8mvRVZZMTlNcTQ5MGs/view?usp=sharin...

At the moment the command "multipath -l" run on hosts shows all the 4 LUNs.

Now I want to do 2 things at storage array level:

- remove the 2TB storage domain LUN - remove the 20Gb LUN not yet allocated

What is the correct workflow, supposing I have already emptied the 2TB from VM disks ad such? Select 2Tb SD, then Datacenter subtab, then "maintenance", detach" and at the end "remove"?

Yes, these should be your first steps.

...

I think I continue to see 4 LUNs at this point, correct?

We do not manage devices, so this must be performed manually by the system administrator. To remove devices, you have to: 1. On the storage server, unzone the devices so the host(s) will not see them This must be done before you remove the multipath device and paths, otherwise vdsm will discover the device again during the periodic scsi/fc rescans. 2. On all hosts ,remove the multipath device and the underlying scsi devices, as explained here: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm... Nir

Yes.

...

Now I proceed with removal of lun at storage array level?

Should I select an SD line and then "Scan disks" to see refresh the SAN and see in multipath only 2 of them at the end? Or any manual command at host level before removal from array?

After removing the storage domains you should be able to remove the luns. I am not extremely familiar with the multipath and low-level scsi commands but I would try the scan disks button and if the luns are not gone from your host you can manually remove them. I think that involves removing the device from multipath (multipath -d) and deleting it from the scsi subsystem.

...

Thanks in advance

Hope this helped you.

_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users

On Tue, Feb 21, 2017 at 5:42 PM, Andrea Ghelardi <a.ghelardi@iontrading.com> wrote:

Hello Gianluca,

I have ISCSI SAN here and not FC but process should be very similar.

Correct operation is

Storage maintenance -> detach -> remove

Once you have removed the storage, Ovirt will release the sanlock.

Note that your server will still “see” the device and multipath will still list it as active.

You can now unmap LUN using your SAN manager.

If your multipath is correctly configured, device will “fail” but nothing else (multipath and server won’t hang).

You will be able to perform basic list operations via server shell without experiencing freeze or locks.*

Yes, but /var/log/messages fills up with multipath errors. This is not desirable

Ovirt will continue to scan new devices so you won’t be able to manually remove them until you unmap devices from SAN manager.

If you need to remove devices manually, it is advised to follow this guide.

https://access.redhat.com/documentation/en-US/Red_Hat_ Enterprise_Linux/6/html/Storage_Administration_Guide/removing_devices.html

* If you do face command freeze etc, re-enable LUN mappings and check your multipath.conf

Yes, but the problem is that I receive error for the LUN previously configured as storage domain. I presume sum stale devices of kind "dm-??" have remained somewhere. I could reboot one ot the 3 hosts and verified that now the layout is correct on it. But I can't easily reboot just now the remaining 2 hosts, so it would be better to find what forces the multipath device in use.... Gianluca

On Tue, Feb 21, 2017 at 7:06 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:

The id of the removed storage domain was 900b1853-e192-4661-a0f9-7c7c396f6f49 and on the not yet reboted hosts I get this The multipath device was 3600a0b80002999020000cd3c5501458f

With pvs command I get this errors related to them:

[root@ovmsrv06 ~]# pvs /dev/mapper/3600a0b80002999020000cd3c5501458f: read failed after 0 of 4096 at 0: Input/output error /dev/mapper/3600a0b80002999020000cd3c5501458f: read failed after 0 of 4096 at 2199023190016: Input/output error /dev/mapper/3600a0b80002999020000cd3c5501458f: read failed after 0 of 4096 at 2199023247360: Input/output error /dev/mapper/3600a0b80002999020000cd3c5501458f: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/metadata: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/metadata: read failed after 0 of 4096 at 536805376: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/metadata: read failed after 0 of 4096 at 536862720: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/metadata: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/outbox: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/outbox: read failed after 0 of 4096 at 134152192: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/outbox: read failed after 0 of 4096 at 134209536: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/outbox: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/xleases: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/xleases: read failed after 0 of 4096 at 1073676288: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/xleases: read failed after 0 of 4096 at 1073733632: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/xleases: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/leases: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/leases: read failed after 0 of 4096 at 2147418112: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/leases: read failed after 0 of 4096 at 2147475456: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/leases: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/ids: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/ids: read failed after 0 of 4096 at 134152192: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/ids: read failed after 0 of 4096 at 134209536: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/ids: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/inbox: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/inbox: read failed after 0 of 4096 at 134152192: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/inbox: read failed after 0 of 4096 at 134209536: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/inbox: read failed after 0 of 4096 at 4096: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/master: read failed after 0 of 4096 at 0: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/master: read failed after 0 of 4096 at 1073676288: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/master: read failed after 0 of 4096 at 1073733632: Input/output error /dev/900b1853-e192-4661-a0f9-7c7c396f6f49/master: read failed after 0 of 4096 at 4096: Input/output error PV VG Fmt Attr PSize PFree /dev/cciss/c0d0p2 cl lvm2 a-- 67.33g 0 /dev/mapper/3600a0b8000299aa80000d08b55014119 922b5269-ab56-4c4d-838f-49d33427e2ab lvm2 a-- 4.00t 3.49t [root@ovmsrv06 ~]#

How to clean?

This is caused by active lvs on the remove storage domains that were not deactivated during the removal. This is a very old known issue. You have remove the remove device mapper entries - you can see the devices using: dmsetup status Then you can remove the mapping using: dmsetup remove device-name Once you removed the stale lvs, you will be able to remove the multipath device and the underlying paths, and lvm will not complain about read errors. Nir

Gianluca

_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users

On Tue, Feb 21, 2017 at 7:25 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:

On Tue, Feb 21, 2017 at 6:10 PM, Nir Soffer <nsoffer@redhat.com> wrote:

...

This is caused by active lvs on the remove storage domains that were not deactivated during the removal. This is a very old known issue.

You have remove the remove device mapper entries - you can see the devices using:

dmsetup status

Then you can remove the mapping using:

dmsetup remove device-name

Once you removed the stale lvs, you will be able to remove the multipath device and the underlying paths, and lvm will not complain about read errors.

Nir

OK Nir, thanks for advising.

So what I run with success on the 2 hosts

[root@ovmsrv05 vdsm]# for dev in $(dmsetup status | grep 900b1853--e192--4661--a0f9--7c7c396f6f49 | cut -d ":" -f 1) do dmsetup remove $dev done [root@ovmsrv05 vdsm]#

and now I can run

[root@ovmsrv05 vdsm]# multipath -f 3600a0b80002999020000cd3c5501458f [root@ovmsrv05 vdsm]#

Also, with related names depending on host,

previous maps to single devices were for example in ovmsrv05:

3600a0b80002999020000cd3c5501458f dm-4 IBM ,1814 FAStT size=2.0T features='2 pg_init_retries 50' hwhandler='1 rdac' wp=rw |-+- policy='service-time 0' prio=0 status=enabled | |- 0:0:0:2 sdb 8:16 failed undef running | `- 1:0:0:2 sdh 8:112 failed undef running `-+- policy='service-time 0' prio=0 status=enabled |- 0:0:1:2 sdg 8:96 failed undef running `- 1:0:1:2 sdn 8:208 failed undef running

And removal of single path devices:

[root@ovmsrv05 root]# for dev in sdb sdh sdg sdn do echo 1 > /sys/block/${dev}/device/delete done [root@ovmsrv05 vdsm]#

All clean now... ;-)

Great! I think we should have a script doing all these steps. Nir

On Wed, Feb 22, 2017 at 9:03 AM, Nelson Lameiras <nelson.lameiras@lyra-network.com> wrote:

Hello,

Not sure it is the same issue, but we have had a "major" issue recently in our production system when removing a ISCSI volume from oVirt, and then removing it from SAN.

What version? OS version? The order must be: 1. remove the LUN from storage domain will be available in next 4.1 release. in older versions you have to remove the storage domain 2. unzone the LUN on the server 3. remove the multipath devices and the paths on the nodes

The issue being that each host was still trying to access regularly to the SAN volume in spite of not being completely removed from oVirt.

What do you mean by "not being completely removed"? Who was accessing the volume?

This led to an massive increase of error logs, which filled completely /var/log partition,

Which log was full with errors?

which snowballed into crashing vdsm and other nasty consequences.

You should have big enough /var/log to avoid such issues.

Anyway, the solution was to manually logout from SAN (in each host) with iscsiadm and manually remove iscsi targets (again in each host). It was not difficult once the problem was found because currently we only have 3 hosts in this cluster, but I'm wondering what would happen if we had hundreds of hosts ?

Maybe I'm being naive but shouldn't this be "oVirt job" ? Is there a RFE still waiting to be included on this subject or should I write one ?

We have RFE for this here: https://bugzilla.redhat.com/1310330 But you must understand that ovirt does not control your storage server, you are responsible to add devices on the storage server, and remove them. We are only consuming the devices. Even we we provide a way to remove devices on all hosts, you will have to remove the device on the storage server before removing it from hosts. If not, ovirt will find the removed devices again in the next scsi rescan, and we do lot of these to support automatic discovery of new devices or resized devices. Nir

cordialement, regards,

Nelson LAMEIRAS Ingénieur Systèmes et Réseaux / Systems and Networks engineer Tel: +33 5 32 09 09 70 nelson.lameiras@lyra-network.com

www.lyra-network.com | www.payzen.eu

Lyra Network, 109 rue de l'innovation, 31670 Labège, FRANCE

----- Original Message ----- From: "Nir Soffer" <nsoffer@redhat.com> To: "Gianluca Cecchi" <gianluca.cecchi@gmail.com>, "Adam Litke" <alitke@redhat.com> Cc: "users" <users@ovirt.org> Sent: Tuesday, February 21, 2017 6:32:18 PM Subject: Re: [ovirt-users] best way to remove SAN lun

On Tue, Feb 21, 2017 at 7:25 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:

...

On Tue, Feb 21, 2017 at 6:10 PM, Nir Soffer <nsoffer@redhat.com> wrote:

...

This is caused by active lvs on the remove storage domains that were not deactivated during the removal. This is a very old known issue.

You have remove the remove device mapper entries - you can see the devices using:

dmsetup status

Then you can remove the mapping using:

dmsetup remove device-name

Once you removed the stale lvs, you will be able to remove the multipath device and the underlying paths, and lvm will not complain about read errors.

Nir

OK Nir, thanks for advising.

So what I run with success on the 2 hosts

[root@ovmsrv05 vdsm]# for dev in $(dmsetup status | grep 900b1853--e192--4661--a0f9--7c7c396f6f49 | cut -d ":" -f 1) do dmsetup remove $dev done [root@ovmsrv05 vdsm]#

and now I can run

[root@ovmsrv05 vdsm]# multipath -f 3600a0b80002999020000cd3c5501458f [root@ovmsrv05 vdsm]#

Also, with related names depending on host,

previous maps to single devices were for example in ovmsrv05:

3600a0b80002999020000cd3c5501458f dm-4 IBM ,1814 FAStT size=2.0T features='2 pg_init_retries 50' hwhandler='1 rdac' wp=rw |-+- policy='service-time 0' prio=0 status=enabled | |- 0:0:0:2 sdb 8:16 failed undef running | `- 1:0:0:2 sdh 8:112 failed undef running `-+- policy='service-time 0' prio=0 status=enabled |- 0:0:1:2 sdg 8:96 failed undef running `- 1:0:1:2 sdn 8:208 failed undef running

And removal of single path devices:

[root@ovmsrv05 root]# for dev in sdb sdh sdg sdn do echo 1 > /sys/block/${dev}/device/delete done [root@ovmsrv05 vdsm]#

All clean now... ;-)

Great!

I think we should have a script doing all these steps.

Nir _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users

Hello Nir, I think I was not clear in my explanations, let me try again : we have a oVirt 4.0.5.5 cluster with multiple hosts (centos 7.2). In this cluster, we added a SAN volume (iscsi) a few months ago directly in GUI Later we had to remove a DATA volume (SAN iscsi). Below the steps we have taken : 1- we migrated all disks outside the volume (oVirt) 2- we put volume on maintenance (oVirt) 3- we detach volume (oVirt) 4- we removed/destroyed volume (oVirt) In SAN : 5- we put it offline on SAN 6- we delete it from SAN We thought this would be enough, but later we has a serious incident when log partition went full (partially our fault) : /var/log/messages was continuously logging that it was still trying to reach the SAN volumes (we have since taken care of the issue of log space issue => more aggressive logrotate, etc) The real solution was to add two more steps, using shell in ALL hosts : 4a - logout from SAN : iscsiadm -m node --logout -T iqn.XXXXXXXX 4b - remove iscsi targets : rm -fr /var/lib/iscsi/nodes/iqn.XXXXXXXXX This effectively solved our problem, but was fastidious since we had to do it manually in all hosts (imagine if we had hundreds of hosts...) So my question was : shouldn't it be oVirt job to system "logout" and "remove iscsi targets" automatically when a volume is removed from oVirt ? maybe not, and I'm missing something? cordialement, regards, Nelson LAMEIRAS Ingénieur Systèmes et Réseaux / Systems and Networks engineer Tel: +33 5 32 09 09 70 nelson.lameiras@lyra-network.com www.lyra-network.com | www.payzen.eu Lyra Network, 109 rue de l'innovation, 31670 Labège, FRANCE ----- Original Message ----- From: "Nir Soffer" <nsoffer@redhat.com> To: "Nelson Lameiras" <nelson.lameiras@lyra-network.com> Cc: "Gianluca Cecchi" <gianluca.cecchi@gmail.com>, "Adam Litke" <alitke@redhat.com>, "users" <users@ovirt.org> Sent: Wednesday, February 22, 2017 8:27:26 AM Subject: Re: [ovirt-users] best way to remove SAN lun On Wed, Feb 22, 2017 at 9:03 AM, Nelson Lameiras <nelson.lameiras@lyra-network.com> wrote:

Hello,

Not sure it is the same issue, but we have had a "major" issue recently in our production system when removing a ISCSI volume from oVirt, and then removing it from SAN.

What version? OS version? The order must be: 1. remove the LUN from storage domain will be available in next 4.1 release. in older versions you have to remove the storage domain 2. unzone the LUN on the server 3. remove the multipath devices and the paths on the nodes

The issue being that each host was still trying to access regularly to the SAN volume in spite of not being completely removed from oVirt.

What do you mean by "not being completely removed"? Who was accessing the volume?

This led to an massive increase of error logs, which filled completely /var/log partition,

Which log was full with errors?

which snowballed into crashing vdsm and other nasty consequences.

You should have big enough /var/log to avoid such issues.

Anyway, the solution was to manually logout from SAN (in each host) with iscsiadm and manually remove iscsi targets (again in each host). It was not difficult once the problem was found because currently we only have 3 hosts in this cluster, but I'm wondering what would happen if we had hundreds of hosts ?

Maybe I'm being naive but shouldn't this be "oVirt job" ? Is there a RFE still waiting to be included on this subject or should I write one ?

We have RFE for this here: https://bugzilla.redhat.com/1310330 But you must understand that ovirt does not control your storage server, you are responsible to add devices on the storage server, and remove them. We are only consuming the devices. Even we we provide a way to remove devices on all hosts, you will have to remove the device on the storage server before removing it from hosts. If not, ovirt will find the removed devices again in the next scsi rescan, and we do lot of these to support automatic discovery of new devices or resized devices. Nir

cordialement, regards,

Nelson LAMEIRAS Ingénieur Systèmes et Réseaux / Systems and Networks engineer Tel: +33 5 32 09 09 70 nelson.lameiras@lyra-network.com

www.lyra-network.com | www.payzen.eu

Lyra Network, 109 rue de l'innovation, 31670 Labège, FRANCE

----- Original Message ----- From: "Nir Soffer" <nsoffer@redhat.com> To: "Gianluca Cecchi" <gianluca.cecchi@gmail.com>, "Adam Litke" <alitke@redhat.com> Cc: "users" <users@ovirt.org> Sent: Tuesday, February 21, 2017 6:32:18 PM Subject: Re: [ovirt-users] best way to remove SAN lun

On Tue, Feb 21, 2017 at 7:25 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:

...

On Tue, Feb 21, 2017 at 6:10 PM, Nir Soffer <nsoffer@redhat.com> wrote:

...

This is caused by active lvs on the remove storage domains that were not deactivated during the removal. This is a very old known issue.

You have remove the remove device mapper entries - you can see the devices using:

dmsetup status

Then you can remove the mapping using:

dmsetup remove device-name

Once you removed the stale lvs, you will be able to remove the multipath device and the underlying paths, and lvm will not complain about read errors.

Nir

OK Nir, thanks for advising.

So what I run with success on the 2 hosts

[root@ovmsrv05 vdsm]# for dev in $(dmsetup status | grep 900b1853--e192--4661--a0f9--7c7c396f6f49 | cut -d ":" -f 1) do dmsetup remove $dev done [root@ovmsrv05 vdsm]#

and now I can run

[root@ovmsrv05 vdsm]# multipath -f 3600a0b80002999020000cd3c5501458f [root@ovmsrv05 vdsm]#

Also, with related names depending on host,

previous maps to single devices were for example in ovmsrv05:

3600a0b80002999020000cd3c5501458f dm-4 IBM ,1814 FAStT size=2.0T features='2 pg_init_retries 50' hwhandler='1 rdac' wp=rw |-+- policy='service-time 0' prio=0 status=enabled | |- 0:0:0:2 sdb 8:16 failed undef running | `- 1:0:0:2 sdh 8:112 failed undef running `-+- policy='service-time 0' prio=0 status=enabled |- 0:0:1:2 sdg 8:96 failed undef running `- 1:0:1:2 sdn 8:208 failed undef running

And removal of single path devices:

[root@ovmsrv05 root]# for dev in sdb sdh sdg sdn do echo 1 > /sys/block/${dev}/device/delete done [root@ovmsrv05 vdsm]#

All clean now... ;-)

Great!

I think we should have a script doing all these steps.

Nir _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users