This is my understanding of how it works:
There are two RAID devices in each box. Each device supports up to 7 drives, and can use RAID 0, 1, 3, 5, 0+1, 10, 30, and 50 with these seven disks. Now, if you want to use the entire 14 in one gigantic RAID setup, you can do that with software RAID (you can do RAID 10, 30, or 50 across the two RAID systems).
This is not actually terribly optical. It is best to use the two RAID systems separately. If you want a gigantic file system, you can use LVM and pull both RAID systems in (probably running RAID 5). However, how I really think it would be most useful would be if we had two database servers. One would run en, and one would run the international wikis. Since the RAID system has two fibre channel ports, you can give each system its own external RAID hardware subsystem in the future. (so, both could have up to 1.75TB of storage at their disposal).
In the near term, just using half the machine (7 disks, just one RAID controller) would still make a huge improvement, I think. It's not the cheapest solution, but it is a lot more reliable than hoping the disks in the servers don't croak, and it gives us the ability to move the database around fairly easily if a server should die (just plug it into a different machine).
-- Nick Reinking -- eschewing obfuscation since 1981 -- Minneapolis, MN
On Jan 12, 2004, at 2:35 PM, audin@okb-1.org wrote:
As to the Apple RAID boxes, my investigations a while back indicated that they are not really redundant. Each box is two seperate RAID devices. So you have to do software raid between them if you want to avoid a single point of failure. This may or may not be a problem, but is not explicitly mentioned in the apple literature. I'm not sure this is a deal breaker, but it is certainly something to think about.