Mike Christie wrote:
> ccing Hannes from suse, because this looks like a SLES only bug.
> 
> Hey Hannes,
> 
> The user is using Linux 2.6.27 x86 based on SLES + Xen 3.4 (as dom0)
> running a couple of RHEL 5.5 VMs. The underlying storage for these VMs
> is iSCSI based via open-iscsi 2.0.870-26.6.1 and a DELL equallogic array.
> 
> 
> On 08/05/2010 02:21 PM, Goncalo Gomes wrote:
>> I've copied both the messages file from the host goncalog140 and the
>> patched libiscsi.c. FWIW, I've also included the iscsid.conf. Find these
>> files in the link below:
>>
>> http://promisc.org/iscsi/
>>
> 
> It looks like this chunk from libiscsi.c:iscsi_queuecommand:
> 
>         case ISCSI_STATE_FAILED:
>             reason = FAILURE_SESSION_FAILED;
>             sc->result = DID_TRANSPORT_DISRUPTED << 16;
>             break;
> 
> is causing IO errors.
> 
> You want to use something like DID_IMM_RETRY because it can be a long
> time between the time the kernel marks the state as ISCSI_STATE_FAILED
> until we start recovery and properly get all the device queues blocked,
> so we can exhaust all the retries if we use DID_TRANSPORT_DISRUPTED.
Yeah, I noticed.
But the problem is that multipathing will stall during this time,
ie no failover will occur and I/O will stall. Using DID_TRANSPORT_DISRUPTED
will circumvent this and we can failover immediately.

Sadly I got additional bugreports about this so I think I'll have
to revert it.

I have put some test kernels at

http://beta.suse.com/private/hare/sles11/iscsi

Can you test with them and check if this issue is solved?

Thanks.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                   zSeries & Storage
[email protected]                          +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)

-- 
You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/open-iscsi?hl=en.

Reply via email to