Software Raid5 On W2kServer

[2canSAM]

Right now my media server is setup with 4 250GB IDE HDD. I am running all 4 off a Promise Fasttrack controller and have 2 mirrored arrays. This give me a total of 500gb of available space. I have my OS setup on a seperate 80gb IDE HDD. I am running Windows 2000 Server and would love to move this to a software Raid-5 setup. I know the performance will less than with a dedicated card. Here is the real dilemma though. If I move all the data files over to one of the 250gb hard drives, then setup my software raid 5 with the remaining 3 disk this would give me an array of 500gb. Would I then be able to add the 4th disk with all the data on it to the system, copy the files to the new array and then once that is done add the 4th disk to the new array? Would there be any issues with me adding the freespace from the 4th drive to the new array?

 

[Lord Evermore]

I believe this will work exactly as you said. Kind of a pain moving all the data to a single drive but otherwise I think it'll work, assuming the RAID in Windows does let you add a drive to a RAID5 array. Verify that first. And of course if the Promise controller happens to offer RAID5, it'll be a lot easier and probably faster.

There shouldn't be any "issues" with adding the 4th drive, it'll just take a long time to process the data to include the new drive, since it has to take the existing data and parity and break it up into one more stripe.

Why do you need the extra 250GB of space if you've already got so little that it fits on a single drive? Aside from just wanting to be as efficient as possible.

 

[spike spiegal]

The four drives in hardware RAID 1 will be faster than 3-4 drives in a software RAID 5.

 

[Madwand1]

Windows RAID 5 apparently doesn't support capacity expansion.

A RAID-5 volume cannot be mirrored or extended.

http://support.microsoft.com/kb/175761/

I can think of a potential workaround, but in any case, I think that you shouldn't be using RAID to avoid having a backup. So I suggest getting another single drive big enough to contain your data, putting it in an external enclosure or another system, backing up to it, and then restoring it as you want. Thereafter, you could use that drive for periodic backups.