Bug#740701: [Netapp-Linux-Community] Bug#740701: multipath-tools: mkfs fails "Add. Sense: Incompatible medium installed"

[Hans van Kranenburg]

On 07/31/2014 10:13 PM, Hans van Kranenburg wrote:
>>>   - Now I'm left with my broken NetApp, and I'd like to start using
>>> UNMAP on it... Any comments from netapp people reading this? There must
>>> be some reason why this is happening, and only on this specific lun, and
>>> not on the test lun, or on several of the other NetApp filer we use.
>>>
>>
>> Yes, the NetApp controllers are returning this MEDIUM ERROR check
>> condition for some reason. I'd suggest you open a NetApp support ticket
>> for tracking this.
>
> And so I did. The answer from NetApp support is:
>
> "Since the UNMAP command is an host OS related command, it is not
> something that we implement in explicitly in Data ONTAP. The
> functionality to support the command is something we do have to test
> however, and any changes or additions to support it are done in new
> releases. This is why you are able to get some functionality out of the
> command in 8.1.2. However, it's not fully certified in Data ONTAP until
> 8.1.3."
>
> So, using UNMAP might work in ONTAP versions before 8.1.3, but it does
> not have an official approval stamp by NetApp.
>
> Also see:
> - https://kb.netapp.com/support/index?page=content&id=3013806
> - https://kb.netapp.com/support/index?page=content&id=3013991
>
> So, although this functionality is reported as 'working' in many cases,
> it seems that NetApp itself has fixed some bugs in 8.1.3 and only then
> officially started supporting using it.
>
> Right now, our idea is to do some upgrades from random 8.1 versions we
> run to the latest maintenance version of ONTAP 8.1 (8.1.4P1), which is
> not a bad idea in any case.

Well, actually it was...

It turns out that, since the upgrade to ONTAP 8.1.4P1, we have this 
issue with UNMAP on all our NetApp filers, instead of only one.

We first did the upgrade to 8.1.4P1 on a system that is hosting backups 
and some office infrastructure, before doing the production systems. 
Looking back, it had been better if we already started testing UNMAP 
again on that one after the first upgrade, because then we would have 
known that upgrading would have actually introduced the same issue there.

Sadly, I was unwittingly assuming that the upgrade would hopefully fix 
the issue, instead of just causing it, so we didn't really extensively 
test on the system that was previously working fine. (argh!)

The only upside of this situation is that I can consistently reproduce 
the error now in a dedicated test setup with some separate physical 
servers and a dedicated test-lun on the backups/office system, where I 
can start playing around, also with multipath/iscsi configuration in 
linux, without having access to any production data.

And I'm trying to get the support ticket at NetApp escalated to the next 
level...

To be continued...

-- 
Hans van Kranenburg - System / Network Engineer
T +31 (0)10 2760434 | hans.van.kranenburg at mendix.com | www.mendix.com