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Increase RAID space question

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Rob Monger_1
Occasional Contributor

Increase RAID space question


I just need some clarification here.

I have a DL380 with 5 of the 6 bays occupied by 18.2GB drives in a RAID 5 configuration. I need to add at least another 40GB of disk space. I have 5 x 72GB drives available and I could install one of those in the empty bay, however I understand that I will only see 18.2GB of that space once it is added to the existing RAID array.

However I have been told from a source which I'm not sure of that I can replace the 18.2G drives one at a time with the 72GB drives allowing each replacement to rebuild before adding the next one. When the last drive is replaced I will have more available space.

If this is true then will the space magically appear in Disk Management in Windows 2000 or will I have to do something in the ACU ?


Greg Carlson
Honored Contributor

Re: Increase RAID space question


I don't believe that to be a true statement, although I could be wrong. However when you have an array with 18gb hdds and you replace them with 72gb hdds, they are striped as 18gb hdds. The only way I'm aware of is to create a new array and restore from backup. If you are able to copy all of your data from your existing array onto your new 1 72gb hdd, then you could always just copy the data over to that one new hdd as a raid 0, then delete your original array and expand the RAID 0 to a RAID 5.

Lets Roll!
Honored Contributor

Re: Increase RAID space question

Both are true. \
If you use a 73 to add to the existing drives, then it is truncated to the size of the group drives were set at.
Replacing all the drives one at a time will produce a RAID 5 of 72GB when the process is finished. The added space will be available as free space to the OS. You can then create new partitions or expand in an old partition.
THis is a common procedure and HP has a document for this, it is available for reading at our site also.
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Rob Monger_1
Occasional Contributor

Re: Increase RAID space question

Thanks guys I appreciate your help.
Jeff Mack
Occasional Visitor

Re: Increase RAID space question

Where would this HP document be for increasing the RAID Array?

Nektar Meletakos
Occasional Visitor

Re: Increase RAID space question

I just completed 2 servers, replacing the existing 4 18gb drives with 4 36gb drives and increasing the partition size.

I used Drive Image Pro to make an image of the compaq system partition, operating system partition and data partition. Then I removed the 4x18gb drives and installed the 4x36gb drives into the bays. On bootup I entered into the array configuration utility and simply created a new raid 5 volume using all the available disks and space.

I then restored the image of the compaq sys partition, os and data(resizing to remaining disk space - 4mb) and voila!!

Easy as pie, if the new disks don't give you prolems like mine did on my 3rd server(3 disks failing!!!)