global hot spare drive

Hi,

Dell is building new domain controller for me. I'd like have global host spare drive in this server.

Config:

Server power edge r620
RAID 1 (OS) - 2x 600 GB
RAID 5 (DATA) 4 x 600 GB

What single drive I should use as global hot spare (what size) and how should be configured (where connected, any raid should be on it ?)

I have pretty hard time to get correct answer from DELL.
thank you,

henry
henryk123Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

PowerEdgeTechIT ConsultantCommented:
It should not be a hard question for the sales guys at Dell to answer.

In order for a disk to be a hot-spare, it must be AT LEAST as large AND the same type (SAS/SATA) as the disks in the array(s) it will protect.

Both of your RAID arrays use 600GB SAS disks, so your hot-spare must be a 600GB SAS disk.  It can be larger, but I'm not sure why you would get a larger one - there is no advantage.

To utilize a hot-spare, you simply assign that role to a disk that is not currently being used in an array:

Global HS:  Will protect both of your arrays.  If a disk fails from either array, the HS will rebuild in its place.

Dedicated HS:  Will protect ONE array - whichever array you assign the hot-spare to.  If you assign the HS as dedicated to the RAID 1, and a disk fails from the RAID 5, then the HS will NOT rebuild in the failed disk's place - ONLY if a RAID 1 disk fails.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
DavidPresidentCommented:
The global hot spare needs to be >= the capacity of the largest disk drive you have in an array with the same technology. If largest SAS disk you have is 1TB then it needs to be >= 1TB.

If you mix & match SAS & SATA then you will need a SAS hot spare and a SATA hot spare.
0
ebad-itCommented:
Hi Henryk123,

Per your current config.  Your primary boot drive containing your OS is Raid 1 meaning they are mirrored.  So, every time something is written to disk 1 the same is written to disk 2. Fast and contains mirror backup.

Your Data volume is Raid 5 which in this case is not really the best situation only having 4 drives.  The minimum drives for Raid 5 is 3 and you can have a hot spare with it or no hot spare at all.  So, if none of these drives are hot spares and a drive fails you stay up but loose a 2nd drive you  will loose all the data.

That is why I would have used all drives in a Raid 5 array with one drive as a hot spare.  Remember with Raid 5 its N-1 with one drive being used for parity.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Server Hardware

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.