Nova iSCSI oddness

Grant Morley grant at civo.com
Wed Oct 28 07:56:17 UTC 2020


Hi Tony,

We are using NetApp SolidFire for our storage. Instances seem to be in a 
normal "working" state before we try and reboot them.

I haven't looked into `/usr/bin/rescan-scsi-bus.sh` but I will now so 
thanks for that.

We are using multipath but kept it on the defaults so it looks like only 
1 path is being used.

I had a feeling it was down to heavily loaded compute causing the issue.

The config for iscsi is also the defaults from which openstack Ansible 
deployed.

Thanks for your help.

Grant

On 28/10/2020 02:25, Tony Pearce wrote:
> Hi Grant, what storage are you using here? Is the instance in an 
> apparently "working" state before you try and reboot it?
>
> Have you looked into `/usr/bin/rescan-scsi-bus.sh` ? Please see this 
> reference link in the first instance: [1] "When ‘rescan-scsi-bus.sh 
> -i’ is run, script execute as well a LIP_RESET (ISSUE_LIP) which may 
> cause a disruption in I/O on the server and even cause an outage in 
> case of a system running on heavy load."
>
> Are you using multipath? Some helpful commands:
>
> `tail -f /var/log/messages | grep multipath`
>
> `multipathd -k` = will go into mutipath cli. Then while in the cli:
> show config
> show paths
>
> If the cli is accessible then you're likely using multipath even if 1 
> path. Then the multipath.conf is taking effect even if it's a default 
> config.
>
> Config files relating to iscsi storage:
> /etc/iscsi/iscsid.conf
> /etc/multipath/multipath.conf
>
> [1] 
> https://www.thegeekdiary.com/when-to-use-rescan-scsi-bus-sh-i-lip-flag-in-centos-rhel/
>
> Regards,
>
> Tony Pearce
>
>
>
> On Wed, 28 Oct 2020 at 03:39, Grant Morley <grant at civo.com 
> <mailto:grant at civo.com>> wrote:
>
>     Hi all,
>
>     We are seeing some oddness on a couple of our compute hosts that
>     seems to be related to iSCSI. On a couple of our hosts I am seeing
>     this error in the nova compute logs:
>
>     2020-10-27 18:56:14.814 31490 WARNING
>     os_brick.initiator.connectors.iscsi
>     [req-8613ae69-1661-49cf-8bdc-6fec875d01ba - - - - -] Couldn't find
>     iscsi sessions because iscsiadm err: iscsiadm: could not read
>     session targetname: 5
>     iscsiadm: could not find session info for session1707
>
>     That seems to also stop any instance on the compute host from
>     being able to reboot.  Reboots seem to get accepted but the
>     instance never completes and gets stuck in the reboot state:
>
>     2020-10-27 19:11:58.891 48612 INFO nova.compute.manager [-]
>     [instance: c8079e85-4777-4615-9d5a-3d1151e11984] During
>     sync_power_state the instance has a pending task
>     (reboot_started_hard). Skip.
>     2020-10-27 19:11:58.891 48612 INFO nova.compute.manager [-]
>     [instance: 31128f26-910d-411f-98e0-c95dd36f4f0f] During
>     sync_power_state the instance has a pending task
>     (reboot_started_hard). Skip.
>
>     Does anyone know of a way to resolve this without rebooting the
>     entire compute host? I can't see any other issues other than the
>     fact there is this iSCSI error which in turn seems to stop nova
>     from processing anything for any instance.
>
>     Any advice would be much appreciated.
>
>     Regards,
>
>     -- 
>     Grant Morley
>     Cloud Engineer, Civo Ltd
>     Unit H-K, Gateway 1000, Whittle Way
>     Stevenage, Herts, SG1 2FP, UK
>     	
>
>     Visit us at www.civo.com <https://www.civo.com/> 	
>     	Signup for an account now > <https://www.civo.com/signup>
>
-- 
Grant Morley
Cloud Engineer, Civo Ltd
Unit H-K, Gateway 1000, Whittle Way
Stevenage, Herts, SG1 2FP, UK
	

Visit us at www.civo.com <https://www.civo.com/> 	
	Signup for an account now > <https://www.civo.com/signup>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-discuss/attachments/20201028/d9434f32/attachment-0001.html>


More information about the openstack-discuss mailing list