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Logical Drive Extension on RAID 5 Configuration

P Kar
Occasional Visitor

Logical Drive Extension on RAID 5 Configuration

I have a RAID 5 array on a Compaq ML 530 with a 3200 SmartArray controller. I have 3 18 GB hard drives with one set as a spare. I am planning on adding two additional 18 GB drives to the array. I would like to expand the existing logical drive to utilize these disks. Compaq(HP) told me they do not reccommend doing this on Win 2000 Server(the OS on my server) as I will loose all the data.

Microsoft says they do not recommend extending the logical drive ONLY if using dynamic disks. My disks are all set up as basic.

Has anyone extended their logical drives without problems on basic disks? What are the advantages/disadvantages of creating a new logical drive on the array as opposed to extending an existing logical drive?

Thanks in advance for any help
Mark Cloutier
Respected Contributor

Re: Logical Drive Extension on RAID 5 Configuration

Since you are using a Hardware RAID, you will have no problems in expanding the original array while your drives are BASIC. If you were using a Software RAID then they would have to be Dynamic. This is where the difference lies. If you create a new logical drive then those 2 drive can be setup as a RAID 1 or you can expand your existing and take advantage of the extra disk space of the present RAID. A disadvantage to expanding is that there is more of a chance of failure but since you have an on-line spare it will reduce this considerably.
You are good to go with either solution with the drives being BASIC since you are running a Hardware RAID.

It is always STRONGLY recommended to have a good valid backup before attempting this.

We are here for a good time, not a long time!
Occasional Contributor

Re: Logical Drive Extension on RAID 5 Configuration


I extend my Logical drive with ACU and I use diskpart (provide by Microsoft) to extend my Windows partition in the unallocated space.

I use Basic disk.

I advise you to shutdown all activity on your Logical drive and backup it and use a "high level of expansion" in the MSA controller parameters.

The time of expension his the same 1 or 10 drives but depending of the disk activity.

For me, 15 hours to extend a RAID 5 from 3 drive of 72 GB to 5 drive in level "Low" and a high disk activity.

5 hours to extend a RAID 5 from 12 to 16 drive of 18GB in level "High" and none disk activity.

I have never loose any data.