[ovirt-users] best way to remove SAN lun

[Nir Soffer]

On Tue, Feb 21, 2017 at 7:25 PM, Gianluca Cecchi
<gianluca.cecchi at gmail.com> wrote:
> On Tue, Feb 21, 2017 at 6:10 PM, Nir Soffer <nsoffer at 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 at ovmsrv05 vdsm]# for dev in $(dmsetup status | grep
> 900b1853--e192--4661--a0f9--7c7c396f6f49 | cut -d ":" -f 1)
> do
>    dmsetup remove $dev
> done
> [root at ovmsrv05 vdsm]#
>
> and now I can run
>
> [root at ovmsrv05 vdsm]# multipath -f 3600a0b80002999020000cd3c5501458f
> [root at ovmsrv05 vdsm]#
>
> Also, with related names depending on host,
>
> previous maps to single devices were for example in ovmsrv05:
>
> 3600a0b80002999020000cd3c5501458f dm-4 IBM     ,1814      FAStT
> size=2.0T features='2 pg_init_retries 50' hwhandler='1 rdac' wp=rw
> |-+- policy='service-time 0' prio=0 status=enabled
> | |- 0:0:0:2 sdb        8:16  failed undef running
> | `- 1:0:0:2 sdh        8:112 failed undef running
> `-+- policy='service-time 0' prio=0 status=enabled
>   |- 0:0:1:2 sdg        8:96  failed undef running
>   `- 1:0:1:2 sdn        8:208 failed undef running
>
> And removal of single path devices:
>
> [root at ovmsrv05 root]# for dev in sdb sdh sdg sdn
> do
>   echo 1 > /sys/block/${dev}/device/delete
> done
> [root at ovmsrv05 vdsm]#
>
> All clean now... ;-)

Great!

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

Nir