P4000 G2 SAN Mixing HardDisk or Hardware RAID Configuration and Hot Spare

[Mi77]

I have 2 questions for P4000 G2 SAN Hardware or Hard Disk RAID and Hot Spare.

1. Does the built-in P4000 G2 SAN controller supports mixing of RAID per node. For example, I have Node A with 12 hard drives, I want to set up 4 hard drives for RAID 10 and the remaining 8 drives for RAID 5. Is this workable? For the second node, I would like to mix the same, is this allowed?

2. Does the built-in P4000 G2 SAN controller supports hot spare. For example I have 12 hard drives in a single node and I want to configure 11 disks for RAID 5 + 1 hot spare, is this workable?

[Patrick Terlisten]

Hello,

the appliances are using Smart Array P400 controllers, so hotspare isn't a problem. But I don't think that different RAID Levels are supported. The storage is pooled on appliance level, so there is no way to choose if data is stores on RAID 5 or RAID 10.

Regards,
Patrick

[teledata]

You don't have the option to choose a single large RAID5 vs a hyrid RAID50, As I understand it generally RAID 5 should not exceed 8-9 drives. I think it is a performance related, and not unique to HP or the P400 controller.

I attached the help section that discusses the RAID configuration options for the various P4000 models. You can ONLY choose RAID configurations that are pre-configured within the management console. You cannot assume you get ALL the RAID configuration options available natively in the P400 RAID controller.

[Mi77]

Thanks Teledata, the attachment is very useful. I believe that whatever is the pre-configured hardware RAID can be changed but cannot mix. Default is RAID 5 though in the CMC we can change it to RAID 10 or RAID 6.

[Bryan McMullan]

Mi77, you are correct. You can change the RAID flavor by dropping the node out of the cluster and rebuilding the array (which will delete all data on it). If you have multiple nodes, it is possible to drop one out switch RAID and put it back in to let it rebuild. (I migrated from RAID10 to RAID5 on a 6 node cluster recently.)

Keep in mind that there's aways an additional (I believe RAID 1) RAID volume that is used by the SAN/iQ software itself that cannot be changed. Beyond that, you can only choose one RAID flavor on the remainder of the disks.

As an aside, Equalogic has the ability to have different RAID segments within a single node, it is quite a cool feature.

[Mi77]

Bryan, your information will help us a lot. Thanks so much