Windows Server 2003 RAID Question

The ToAsT · 7 Feb 2006 at 19:06

I'm hoping that one of the technologically gifted that frequent these parts will be able to help me with this...

I look after a file server, which is based on a RAID-10 array of 4 x 200Gb disks. This gives us useable filespace of 400Gb. The disks are connected to a 4 port 3Ware Escalade RAID controller, and the whole lot is running under Windows Server 2003. These four disks are the only ones in the machine, so the o/s boots off a small C: partition on the array and all the user filespace is on the D: partition.

The problem we are up against is that the filespace is getting very full, and we now need more space. My general question is this - how best to achieve the required increase in filespace without too much buggering about or expense? There is too much data to do a backup and restore easily (although this is I suppose possible for the user filespace partition) but I cannot afford to lose the settings in the boot partition - usernames, passwords, config that sort of thing.

My specific questions are these -

1. If I buy 4 x 400Gb drives, and hot-swap them one-by-one with the existing 200Gb drives (allowing an array rebuild between each swap), will the array magically become 800Gb in size after the fourth swap? Or will it stay at 400Gb with a further 400Gb of unuseable space?

2. If I buy an 8 port RAID controller, and attach my existing 4 drives plus 4 new ones, will my current partitions show up and operate normally?

3. I I buy another RAID controller and some new drives to use in addition to the ones I've already got, is there a means to merge them all into the same partition (i.e. so that the users only see one consolidated filespace).

4. Could I use Norton Ghost to back up my C: (system) partition to an IDE hard drive (which I can attach easily), swap all the 200Gb drives out for 400Gb ones, build a new RAID-10 array, and then restore my original C: partition?

AndyC · 7 Feb 2006 at 19:48

Sure 1 and 2 sure won't work, 4 sounds abit risky, I would suggest adding another card with more disks but it just doesn't seem like a good idea, is this in a proper server ( I assume its is with hot swap) as you maybe limited to how many disks that can be installed.

We have come across this a far bit where all data and the OS are on the same physical drive and partitioned and it’s a nightmare - usually put in a new machine in the end - tend to also be a few years old also with one array for the OS and another for the data, but as you state a rebuild is not an option,

Sure someone else can help you thou.

Magsy · 8 Feb 2006 at 14:21

1. Will work fine, you will have additional space to create another partition - it will not extend what you have.

2. If software raid it will work, if hardware then probably not, hardware arrays very rarely work on another controller.

3. See above.

4. Yes the best choice by far, I don't see how it is risky at all provided you put the Ghost image on a good reliable drive and verify its integtrity before wiping the drives. Your post is not clear but I assume you are talking about Ghosting the whole set of drives, both C and D

You could do option one, the nuse something like Partition Magic to expand the current partition into the new space. This is risky though as partition altering can result in total loss. Backup first.

If you REALLY need Raid 10 then you should have a method to back that server up, no excuses!

The ToAsT · 8 Feb 2006 at 17:11

Cheers both of you for your help. I'm going to go with the Ghost route, I think. The RAID controller is a 3Ware Escalade 7506, and I've since found out that it won't tolerate online expansion by swapping out bigger drives.

Backup solution is no problem, I have an offsite service that takes care of that. I'll Ghost the C: system partition to a local IDE drive, and the D: user partition is backed up anyway. Just need to find a good deal on 4 really big hard drives now...

Thanks again.

Skilldibop · 9 Feb 2006 at 12:21

you can't hot swap unless your in Raid5 even then the disks need to be identical to the others.
Raided disks arn't partitioned. Windows sees them as one big disk which is then partitioned. This is entirely logical and there are no physical partitions on the disks.

you can't merge an array into another without first wiping the disks clean as the data distribution will be uneven and it just won't work.
As far as i'm concerned the only way is to either physically copy the data to another Box and pull it across to the new rig once the array is set up and partitioned. Or do the same thing using ghost.

We just migrated a system which involved storage upgrade. Worked out easier to replace the whole server and just drag data across a gigabit crossover lead.

Magsy · 9 Feb 2006 at 21:30

That is not correct, you can replace a drive in a raid 5 array on most controllers or software raid with a drive of equal or larger size. I have done many swaps in servers, specifically old ones where you cannot easily get the same drives.

Dimension · 10 Feb 2006 at 09:27

you should be able to replace the drives with bigger drives 1 at a time without data loss and have 400gb unused space that can be used for another raid array.

give 3ware a call, their tech support is 1st class and will let you know what your card can and cant do

Skilldibop · 10 Feb 2006 at 16:00

yeh but it'll only use however big the old drive was. Thus to get the 400GB disks working fully you need to re-do the array which will undo your data. It's ok to do it, but it won't achieve what he wants.