Ashley M. Kirchner wrote:
I'm looking at setting up a RAID system for doing video work. My two
main requirements are speed and reliability. Speed is an issue because
of the constant streaming of hundreds of megabytes, if not gigabytes of
data that is inherent with video. And obviously reliability, I want to
make sure I don't lose any data of a drive crashes on me. This will
also be a hardware RAID solution (as opposed to software) and, depending
on funds, I may try to make it a hot-swappable system.
fast - reliable - inexpensive. pick two.
But unless you are running multiple video feeds into the disk at one
time, fast isn't an issue. Commodity SATA drives will do 50MB/s without
effort, and 200MB/s is readily reached using software RAID. If you want
fast and reliable, go SCSI. Until recently I ran 20+ servers for an ISP,
with 6M users, and 2-6TB/server. There isn't a non-SCSI RAID card I can
recommend (that does NOT mean they don't exist, I just didn't find one).
If 150MB/s write and 200+ read with good reliability will do, go
software RAID-6 for the data, RAID-1 (three way if you're paranoid) for
the o/s and swap.
Hardware RAID is very good, but the "firmware RAID" on motherboards and
cheap controllers are not usually fast OR reliable enough. Use a lot of
memory. No, more than that.
Based on all the different RAID levels out there, what does the
collective suggest? 1? 3? 5? 0+1?
cheap: RAID-5
reliable: RAID-6+hot spare
fast and reliable: RAID-10+2xhot spare, RAID-1 for bot/root/swap
For SCSI I have had good luck with the "ServeRAID" IBM controllers.
They're Adaptek with IBM firmware hacks, I believe.
--
Bill Davidsen
He was a full-time professional cat, not some moonlighting
ferret or weasel. He knew about these things.
