RAID 0 with partitions - partition drives before making raid?

I am planning on using 2 320gig drives for a RAID 0 setup, but I want the raid to be partitioned. Do I partition the drives with 2 exact partitions first, and then combine each partition into a raid, or do I make the raid first, and then partition the virtual disk?

And if I do partition first before making the raid, can I do that right from OSX, or should I do it from the boot DVD disk utility?

well this is interesting

I made the partitions first, 3 of the same size (as close as I could get in disk utility) in 50, 100, and whatever is remaining gigs. I was able to raid the first 2 partitions, but not the last, they were just disks

so I reformatted the drives as 1 partition each, raided them, but now I can't partition that raid.

Did I do something wrong the first time, where I couldn't raid the final partitions on each drive?

Okay, retried partitioning the drives first (read that it doesn't always work exactly) and I was able to make 3 partitions each, and combine them into 3 striped raid volumes.

So now, I have the 3 volumes I wanted, each a striped pair of partitions.

Although, Disk Utility did crash on me when it was finished. I reopened it and it appears fine. Wasn't very confidence inducing, but something risky like a raid with partitions is risky I guess.

Anyone want to comment on this? Is this normal for something of this nature, to not be an exact science to set up?

pengu said:

RAID is generally done on entire disks, not partitions... can't think out why you can't partition if afterwards :S

Click to expand...

I don't know, but disk utility didn't have an option to partition a raid once it was created.

After pre-partitioning the drives the exact same, the second time I tried, it worked and now I have 3 volumes running off the same raid.

That's what I read in this article: http://macprojournal.com/partitions.html

maybe if there is a way to partition the raid after you create it, someone could shed some light on that.

In case anyone was reading this thread, I was able to successfully partition 2 drives and create 3 virtual raid0 drives out of them.


So far, it's really fast. The benchmark numbers I have been using are a great deal higher than before, and the speed that my files and things load and read/write is increased too.

If you have a good backup solution, I think I would recommend at least 1 raid0 setup in a Mac Pro.