VA7400 and adding different disk drives

[Sylvia Welch]

I currently have a VA7400 with 24-36GB drives. We have
6 slots open for more drives. We are at just below 50%
usage on the array, keeping us at Raid 1+0. We need
to add another 300GB of storage. I was thinking of
picking up 6 144GB drives to keep my RAID 1+0 and
satisfying the space requirement. Is this do-able?

P.S. This thread has been moved from General to Disk array. - Hp Forum Moderator

[Karthik S S · Accepted solution]

Hi,

yes it is possible. Pl. make sure you go through the following threads,

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=495850

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=60825

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=196524

-Karthik S S

[Karsten_4]

Hi,

I am not absolutly sure, but I think the 146GB/10k and the 73GB/15k Drives are not supported in the VA 7100 and 7400.

You can use the 73GB/10k Drives.

But be aware that probably you will not gain as much Space as you expect. Depending on the Array Raidlevel (0/1 or Autoraid) and the Position where you put the Drives (i.e. whitch red. Group) you will have more or less free space.

[Michael Schulte zur Sur]

Karthik,

your first posted thread states, also confirmed by Karsten, that 146GB disks are not supported by the VA7400.

sorry Sylvia, you will have to look for something else.

greetings,

Michael

[Karthik S S]

Michael,

Thanks for catching my mistake .. :-( .. I got confused b/w VA7400 and VA7410

http://h20000.www2.hp.com/bc/docs/support/SupportManual/lpg60187/lpg60187.pdf

Page no:17

146GB disks are supported only on VA7110 and VA7410.

-Karthik S S

[Peter Mattei]

Yes, you can do it, but be careful!
You will not gain as much space as you would think by just plugging the 6 disks.

Reason: I assume you are a good citizen and have hot sparing enabled. I guess you left it to automatic.
For up to 15 disks in a redundancy group (RG) this will reserve one time the capacity of the largest disk in this RG. I guess you have 12 disks in RG1 and 12 disks in RG2.
So you have 36GB reserved in each RG for sparing.
Note: Starting with the 16th disk the VA will reserve 2 times the capacity of the largest disk, thus if you added disk 16 in an RG (with the same capacity) you would not gain space at all!
You can manually set the VA to only use one spare per RG. This behavior has been implemented to cover the higher risk of two disks in an RG to fail.

Now, let us assume you add one 144GB disk to an RG. The VA now has to reserve space for the larger drive. The result will be LESS capacity than before!
If you do that in both RGS you will end up with much less usable capacity.

You will get the best net space increase by adding all 6 144GB disk to one RG only.
See the attached drawing I made.

Have fun
Peter

PS: I suggest you also have a look at the VA Users Guide on
http://h200005.www2.hp.com/bc/docs/support/SupportManual/lpg60187/lpg60187.pdf
In chapter 2 it tals about how the VAs work!

[Peter Mattei]

Uups, I also missed the point - VA7400 not VA7410!!

You now have the option to upgrade your VA7400 using 12x 73GB disks and add a DS2405 enclosuer or you could upgrade the VA7400 to a VA7410 and then use 146GB disks (more expensive and disruptive).

Sorry
Peter

[Sylvia Welch]

Thanks for all of your help. Guess will need to upgrade the 36GB to 72GB