topic Re: expand array in Disk Enclosures

expand array

dave.b — Mon, 23 Jul 2007 08:33:44 GMT

Hi all
I've msa1000 with 2 drives in raid 1. ( the drives are 146GB ). In this array I've 3 LUN.
I add 1 drive ( 146GB )and i wish expand array and migrate from raid 1 to raid 5.
My question: after expand array, i Migratre each LUN from raid 1 to raid 5, or is not necessary ?

Re: expand array

e4services — Tue, 24 Jul 2007 08:59:18 GMT

Remember, there is a RAID logical and an OS logical (LUN). You will be expanding the RAID logical when you add the drive, creating a larger drive. THis will not effect the LUNs of the OS, simply add more space to the drive which will appear as free space to the OS and must be partitioned and formatted.

Re: expand array

Puneet Arora — Tue, 24 Jul 2007 22:48:18 GMT

Sorry but the answer by e4services is not for this query...
To answer your question, remember that the way Smart Array/MSA1000 controllers work is that the data is spanned across all the HDDs in the array.
So the moment you add another Hard drive to this array, the total number of HDDs will be 3, since you cannot have RAID 1 with 3 HDDs, the controller will migrate all the logical drives to RAID 5 automatically.
So ideally it is not neccessary for you to go through the migration process.
You can confirm this by looking at the ACU after expanding the Array.