Enabling AutoRAID 12H hotspare

[Brian Kennedy]

Hello,

I am owning two AutoRAID 12h diskarrays.
This week-end, I copied all data from AutoRAID 1 to AutoRAID 2.
On AutoRAID 1, I have active hotspare enabled, but not on AutoRAID 2.

My question is: if I disable active hotspare on AutoRAID 2, how can I take these disks out the AutoRAID 1, in order to enable hotspare on AutoRAID 2, WITHOUT destroying datas on AutoRAID 1? i.e. AutoRAID 1 would have the same datas as AutoRAID 2, but AutoRAID 1 would have active hotspare disabled.

Thanks for help !

Regards,

//Brian.

[Andreas Voss]

Hi,

hotspare on an AutoRAID is not a single drive, instead the AutoRAID uses all included drives for hotspare.
If you enable hotspare the AutoRAID will try to free particular space on all drives with the capacity of the biggest drive included in the AutoRAID.

Regards

[Bill McNAMARA_1]

To enable hotspare:

# arraydsp -i
Record the serial number
# arraymgr -h on SERIALNUMBER

done

Or
go up to the Control Pannel
And set ActiveSpare to enabled,
I think it's in the Disk Changes Section.. or
in Ctrlr Changes..

Or do it through SAM-> Disk and File Systems ->
Options-> Maintenance

Make sure you have enough space to do it, because hot spare requires disk space.
Check if you have from the capacity planning tool:
http://www.hp.com/essd/capacity.html

To see how much space you have:
arraydsp SERIALNUMBER

Later,
Bill

[Bill McNAMARA_1]

The autoraid doesn't not use the disk space.
It uses it for RAID 0/1 storage. There is not
unallocate disk space when the active spare is on. It just means it's raid 0/1 not raid 5.
Thats a good thing for performance, but less
efficient in terms of disk space. But it's
a good trade off seeing as its a good HA
feature to have Active spare in anycase.

When a disk fails on the 12H It'll 'make' the
space by moving all the data that was in RAID 0/1 to raid 5 making more efficient use of
the left over disk space. The data will then
be N+1 after the rebuild again.

It's the greatest!

Later,
Bill

[Bill McNAMARA_1]

yea, hotspare is not a dedicated drive.
You can't unplug it. The capacity planning tool should make it a little clearer.

Bill

[Brian Kennedy]

Andreas,

The thing is that I have several 18.2Gb drives and 9.1Gb drives.
What I'd like to do is:
* disable HotSpare (i know how to do that)
* down two 9.1Gb drives (9.1Gb * 2 = 18.2Gb, i.e. biggest space found on a single drive) from AutoRAID 1, and insert them into AutoRAID 2
* enable HotSpare on AutoRAID 2

So how can I down/exclude two disks on AutoRAID 1 without destroying datas on it ? That is to say: Autoraid 1 will function without hotspare enabled, so having enough space to store all its data.

Thanks for help !

Brian.

[Bill McNAMARA_1]

No you can't.
The AutoRAID disks are N+1
When a disk fails/removed hot spare or none
the array will try to rebuild. The data is
not N+1. Failing another while
arraydsp SERIALNUMBER
says there's a warning or when a rebuild is
required (always the case immediately after one fail) will result in data loss.

Summary:
2 disks failing BEFORE REBUILD COMPLETE
at the same time is data loss hot spare on
or off.

Later,
Bill