[dm-devel] [PATCH v5 3/3] dm mpath: add CONFIG_DM_MULTIPATH_SG_IO - failover for SG_IO

[Paolo Bonzini]

On 02/07/21 16:21, Martin Wilck wrote:
>> SG_IO gives you raw access to the SCSI logic unit, and you get to
>> keep the pieces if anything goes wrong.
> 
> That's a very fragile user space API, on the fringe of being useless
> IMO.

Indeed.  If SG_IO is for raw access to an ITL nexus, it shouldn't be
supported at all by mpath devices.  If on the other hand SG_IO is for
raw access to a LUN, there is no reason for it to not support failover.

Paolo