Re: How to resurrect offlined SCSI devices?

[Mike Anderson <andmike@us.ibm.com>]

James Bottomley [James.Bottomley@steeleye.com] wrote:
> I'd really like to see all fibre events (like loop up/down, device
> add/remove) handled inside the FC transport class.  From there, it
> probably still make sense to use hotplug as the mechanism for importing
> user policy.

Currently there are no hotplug events generated from SCSI except those
from add / remove of sysfs related structures. Are you suggesting that
SCSI should call call_usermodehelper and generate events?

The general issue I believe Martin is investigating is in the context of
device mapper multi-path (Martin correct me if I have this incorrect).
In the failure transition of a path a scsi_device can be marked
offline.  Until the device is restored path checking / re-enablement
cannot proceed. One issue is that path testing tools need to have SCSI
specific knowledge to know to change a device state. The second issue is
that while this could be done with a daemon it would appear a more
efficient method would be some form of state / event notification of
device and transport specific events.

-andmike
--
Michael Anderson
andmike@us.ibm.com