[stgt] Late opening of the backing store

[Môshe van der Sterre]

On Thu, 19 Jan 2012 08:14:28 +0900, FUJITA Tomonori
<fujita.tomonori at lab.ntt.co.jp> wrote:
> On Wed, 18 Jan 2012 23:43:51 +0100
>> Manually, this is possible, however, the administration tool (LVM for
>> example) can't do this.
>> This is the issue I am trying to solve. udev triggers would work great
>> for this.
> 
> Hmm, I guess that you can easily write your own administration tool
> (that could call the existing tools).
> 
>> >> Is short this means stgt should defer the open() call on the backing
>> >> store until a connection is requested. Likewise, it should close() the
>> >> backing store when the last connection closes.
>> >> I am guessing such a feature does not yet exist (I couldn't find it),
>> >
>> > tgt supports such feature for MMC logical units. But what tgt should
>> > return to initiators when the initiators try to access to devices that
>> > are not available?
>>
>> I am not sure (I don't know that much about the internals of iSCSI), I
>> suppose the same thing as would happen now if a backing store is
>> unplugged/truncated while stgt has opened it?
>> Is this an error condition that is not possible with iSCSI?
> 
> It's not about iSCSI but SCSI. Ronnie gave some hints. If you give me
> pointers in the SCSI specs that this behavior is ok and send patches,
> then I'm not against merging them.

Ok.
I'll look into it some more (but it might be a while before I do).
I think this is a more general solution than adding stgt specific hooks
to other tools, but I'll take the consequences it has on SCSI into
account.

Thanks,
Môshe van der Sterre
--
To unsubscribe from this list: send the line "unsubscribe stgt" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html