[Pkg-iscsi-maintainers] Bug#584999: open-iscsi: no diagnostic of broken targets

[Michal Suchanek]

Excerpts from Ritesh Raj Sarraf's message of Wed Jun 09 22:14:12 +0200 2010:
> On Thursday 10 Jun 2010 01:29:57 Michal Suchanek wrote:
> > > You can always be logged into the target, for example, to test if the
> > > auth models are working or not. It does not have to reflect a device
> > > appearance on the initiator.
> > 
> > And then you if no device appears how do I determine why it did not
> > appear?
> >
> 
> You need to check on the target if there's any LUN associated for your 
> initiator's IQN.

Why can't I check on the initiator if there are any associated LUNs?

>  
> > I don't see any option for listing a target's luns so there is no way to
> > tell if the targets has no luns or attaching the target failed in some
> > unusual way.
> >
> 
> The initiator should not be allowed to see a listing of all of the target's 
> LUNs. It should only be allowed to see if there are LUNs available for it.

All the same I don't see any way how to tell if there are any available
or not.
> 
> You need to diagnose that in the target's logs. If there are LUNs on the 
> target but are not part of the IQN of your initiator, you will not see any 
> LUNs.
>  
> > > Nothing to do with the initiator.
> > 
> > Except it attaches the luns to the system. Otherwise it is completely
> > unrelated to the target and its luns.
> > 
> 
> I don't understand this part. You login and see LUNs on the initiator ?

Yes, they are attached as scsi disks if things work as expected. If they
don't there isn't much to do on the initiator to determine why.

It's possible to check the target logs if they are readily available
but there are times when this is not the case like when the
administrator of the target is somebody else, you are using a dedicated
hardware rather than a software implementation, etc.

Even when the logs are available it's good to have diagnostics on both
sides. It eases diagnostics of both user errors and actual bugs.

Thanks

Michal
-- 
Michal Suchánek
michal.suchanek at ruk.cuni.cz
tel 224491810 fax 224491594
Univerzita Karlova v Praze
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