I’ve been deploying Celerra’s for a while now and with technology changing as fast as it does, you really need to be across the applied practice, best practice and NAS Matrix documents found in PowerLink to validate your storage design.
For the last couple of years the majority of the Celerra’s Ive deployed have been shipped with DART 5.6 code and the backend Clariion flare version has typically been what we refer to as 28,29 and most recently flare 30.
One of the first things you learn when deploying Celerra’s is you need to read the NAS Matrix guide to determine which RAID configurations are supported because although you may be able to create certain RAID types with x number of disks on the backend Clariion, It doesn’t mean the Celerra will let you use it… this is typically where people sit for 20-30 mins performing multiple “rescan storage” operations hoping that storage will magically appear.
One of the biggest changes in Flare 30 was the introduction of storage Pools which is quite different to the traditional “Raid Group” concept which has been around for donkeys years. If you want to read a bit more in-depth information about Storage Pools, then check out Matt Hensleys post here.
What I couldnt find in the latest NAS Matrix guide or in any of the documentation I found was conformation that I could present storage from the Clariion storage pool to the Celerra, so after carving a LUN from the storage pool made up of 10 FC disks, I presented it through to the Celerra and performed a rescan…… rescan…… and one more for good luck…..rescan, but unfortunately no luck and no LUN.
At this stage I remembered often performing tasks from the command line on the control station often spits out more debug information so I thought id give it a shot.
And that confirmed it. ” Fully provisioned CLARIION pool device was not marked because it is not supported in this realease”
The answer to this problem in the end was “thin provisioning”. I created a thin provisioned LUN from the Clariion Pool, added the LUN to the Celerra storage group and performed a rescan and there was my LUN.
In the end I found the following primus solution EMC241591 which outlines 3 conditions that will cause this error, fully provisioned LUNs was one of them along with Auto Tier and Compression being enabled.
Cause : Certain new CLARiiON FLARE Release 30 features are not supported by Celerra and the initial 6.0 NAS code release. CLARiiON LUNs containing the following features will not be diskmarked by the Celerra, resulting in diskmark failures similar to those described in the previous Symptom statements:
- CLARiiON FAST Auto-Tiering is not supported on LUNs used by Celerra.
- CLARiiON Fully Provisioned Pool-based LUNs (DLUs) are not supported on LUNs used by Celerra.
- CLARiiON LUN Compression is not supported on LUNs used by Celerra.