The consideration for AutoRAID extend

[Jack Fan]

Dear all,

What is my consideration for AutoRAID 12H extend? I have one disk array 12H and have 8*18GB disks on it. Now, I need for extend space capacity for production. Which one is better for performance and capacity? add 2*36GB or 4*18GB?

Thanks In Advance!

Jack Fan

[harry d brown jr]

It's almost always better to add more spindles, so the 4*18gb drives is better than 2*36gb. The more spindles (disk drives) the more the 12H can handle.


live free or die
harry

[Jack Fan]

Dear Harry,

Thanks for your quickly response. But I also want to know the further technical information about this. Or it is simply on spindle consideration. Your answer will be appreciated.

Jack Fan

[harry d brown jr]

Jack,

here's the 12H info library:

http://www.hp.com/products1/storage/disk_arrays/midrange/12h/infolibrary/index.html


Live free or die
harry

[Jack Fan]

Dear Harry,

How about these question as below?

1. Is this 18GB disk obsoleted?
2. Have any performance issue when the same time 18GB and 36GB on 12H?

Thanks,

Jack Fan

[Hartmut Lang]

If you install 2*36GB you will only have 1*36GB more capacity available.
The other 36Gb disk will be needed for achieving the RAID protection. A 36Gb disk can only be proctected by another 36Gb disk.
So to extend space, the 18Gb disks will give you more capacity.

Hardy

[Xavier Gutierrez]

Don't worry about disk failure and substitution.

AutoRAID reserves enough space to replace the biggest disk in the array.

Failed disks are not replaced in a by disk basis, but distributing the data across all the other disks.

Failure of a disk will make AutoRAID migrating some of the data from RAID 1/0 to RAID5 automatically (as long as you have the active spare option enabled).

Regards,

Xavier