How to split up this 7TB Raid?

[CharlieX]

Right off the bat, 4 systems editing a feature film at DV50 @ 23.98 fps (~6MB/s).

7TB Xraid in the mail (along with the entire Xsan setup). Can't afford anything else until we sell this project.

Take 2 drives for MDJ, that leaves 5 on one side. Remove 1 for Hot Spare. So I have 4 drives ~ 2TB. ....But then how to treat the other side with the 2TB limit on a LUN?

OR, can I split that MDJ pair across the two controllers? Which would leave me 6 drives per, down to 5 with HS, which might be sub 2TB after RAID 5?

Thanks for clearing up my brain!

[bforcier]

you basically have just 2TB usable since it's not recommanded at all to setup an Xsan with just one XServe RAID 14*500...

if you try to create 2 LUNs on the other side (1 for MDC, 1 for rest of drives) you'll have a major performance issue since you'll be assigning 5 drives to a RAID5 LUN of 2 TB and 2 drives to a RAID1 LUN of 500GB. The controller will be sending info to both LUNs at the same time hence you WILL drop frames (not might or maybe but WILL).

I would tell you to buy a second Xserve RAID with 7*400, recupe the 3 extra 500GB drives (1 from each controller) and put them in the empty controller thus creating 3 RAID5 LUNs of 2TB for Media and 1 RAID5 LUN for MDC.

This helps you get optimum output and performance from 2 Xserve RAIDs and achieve 6TBs usable without wasting drives...

I would even buy an additional 500GB HD in order to have an hot spare in all my LUNs...

[CharlieX]

thanks for the reply. That's the number I came to... 2 whoppin' TBs. Well, when the money fairy comes back, another XRAID gets added to the SAN.

I figured splitting the LUN for the MDC would cause traffic hiccups. The little things they "forget" to mention at Apple.

[tantumonium]

I've been working on setting up an Xsan w/ a 14x500GB RAID. I'm not using this in a video environment, so I can't say what your performance will be, but for me... capacity matters more than raw speed.

What I've done is to format the 7 disks (or 6 w/ Hot Spare) together as RAID 5, and then using the Disk Utility program, sliced it into two partitions. Both resulting partitions are under the 2TB limit, each are given a unique LUN number, and are recognized by Xsan without issue.

The performance I've gotten so far seems fine, and the 5.42TB of total space is nice as well.

NOTE: I'm not storing my Metadata on any of those LUN's. I've got half of an older Xserve RAID for that.

[Guest]