Re: [PATCH] sd: do not set changed flag on all unit attention conditions

[Hannes Reinecke <hare@suse.de>]

On 07/17/2012 11:59 PM, James Bottomley wrote:
> On Tue, 2012-07-17 at 12:36 -0400, Christoph Hellwig wrote:
>> On Tue, Jul 17, 2012 at 10:11:57AM +0100, James Bottomley wrote:
>>> There's no such thing in the market today as a removable disk that's
>>> resizeable.  Removable disks are for things like backup cartridges and
>>> ageing jazz drives.  Worse: most removeable devices today are USB card
>>> readers whose standards compliance varies from iffy to non existent.
>>> Resizeable disks are currently the province of storage arrays.
>>
>> The virtual disks exported by aacraid are both marked removable and
>> can be resized.
> 
> So what are properties of these things? ... or is this just an instance
> of a RAID manufacturer hacking around a problem by adding a removable
> flag?
> 
Presumably.

The general intention is to automatically catch any disk resizing.
As the SCSI stack (used to) ignore these things that was their way
of working around it.

Curiously, though; the aacraid driver is the only one doing this,
plus the process is quite involved (using a proprietary application
for doing so etc).

None of the FC driver do this, despite the fact that resizing a disk
is even easier here.

I even tried to remove that line once, but then got told off by then
Adaptec that I would break their apps.
Since then there's a patch in the SLES kernel for adding a module
option switching off this behaviour.

We should ask Adaptec/PMC-Sierra here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
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