Expand RAID5 Array

[Brad Reichert]

I've got a Compaq ML370G2 with 3 drives in a RAID5 array connected to a 5i
controller. How do I go about adding a 4th drive to the array? Is there
an application like in NetWare (cpqonlin.nlm) to do this?

Thanks,

Brad

 

[David H. Lipman]

I think you should be asking Compaq if this is Compaq hardware.

Dave



| I've got a Compaq ML370G2 with 3 drives in a RAID5 array connected to a 5i
| controller. How do I go about adding a 4th drive to the array? Is there
| an application like in NetWare (cpqonlin.nlm) to do this?
|
| Thanks,
|
| Brad
|
|

 

[Lanwench [MVP - Exchange]]

With hardware RAID, this wouldn't be done in the OS, anyway.
I don't think you can just add another drive to an existing array, but check
your documentation & check with Hpaq.

 

[Kris Shaw]

Hi,

I've done this on a Compaq ML570 connected to a Smart Array 5300 -
perhaps your ML370 works in a similar way? Anyway, witht he 570 you
just simply plug in the new drive and expand the RAID 5 array using
the Array Configuration Utility (ACU, d/l from HP if not already
installed).

Note that expanding the array does not always increase the partition
size, you may need a tool such as partition magic to do that.

As always - backup!

Kris.

 

[sandywu]

expand raid in a safe mode

Unless the Highpoint controller supports a RAID expansion feature - there isn't any direct method if you want to maintain the RAID-5 fault tolerance.

The only other way is to first backup the array data. Then delete the 3 drive array and re-create it as a 4 drive array. Restore the data to the new larger array and you're good to go.

Note if you add a disk that's larger than the other disks, it will be resized to match the capacity of the others. In other words, if you have 3 36 GB disks and add a 73 GB disk you will only be able to use 36 GB of the 73 in your new configuration. The remainder will be unusable.

Some partition software will help you to backcu and repartition the raid 5, such as acronis discdirector, easeus partition master, yo may also find a solution here:

http://techrepublic.com.com/5208-7343-0.html?forumID=101&threadID=272843&messageID=3146481

 

[zhuq]

"How do I go about adding a 4th drive to the array?" it depends on which raid card you are using, some can rebuild the raid array after add the new drive without data loss, but some cannot. you should make clear about this. After you add the new drive to the array, the space will be displayed as unallocated and you can create or resize either partition with this space without difficulty.
Do not know whether Brad Reichert needs to resize the partitions, if yes, see this article, it is helpful doing this. http://www.partition-tool.com/resource/expand-raid5-partition.htm