Re: [dm-devel] LSF: Multipathing and path checking question

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Mike Christie wrote:
> Mike Christie wrote:
>>> For starters we just should send a netlink event when fast_fail_io has
>>> fired. We could easily integrate that one in multipathd and would gain
>>> an instant benefit from that as we can switch paths in advance.
>>> Next step would be to implement an additional sdev state which would
>>> return 'DID_TRANSPORT_FASTFAIL' for any 'normal' I/O; it would be
>>> inserted between 'RUNNING' and 'CANCEL'.
>>> Transition would be possible between 'RUNNING' and 'FASTFAIL', but
>>> it would only be possible to transition into 'CANCEL' from 'FASTFAIL'.
>>>
>>
>>
>> Yeah, a new sdev state might be nice. Right now this state is handled
>> by the classes. For iscsi and FC the port/session will be in
>> blocked/ISCSI_SESSION_FAILED. Then internally the classes are
>> decieding what to do with IO in the *_chkready functions.
>>
>>
> 
> 
> How about setting the device to the offline state for this case where
> fast_io_fail has fired but the dev_loss_tmo has not yet fired? As fast
> as failing IO we get the same result. scsi-ml would fail the incoming IO
> instead of it getting to the class _chkready functions, but the scsi
> device state indicates that it cannot execute IO which might be nice for
> users.
> 
Ah, no. OFFLINE is a dead end status out of which we cannot transition
from inside the kernel. I'd prefer a new state here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@xxxxxxx			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux