OT: ATA RAID controllers (was: Re: [Pan-users] Speed of pan)

[Carl Wilhelm Soderstrom]

> Of course, if anyone still wants more speed like referenced in that
> last message in this thread about the fibre channel array, take a
> Highpoint or Promise IDE RAID controller 

avoid Promise RAID controllers! (certainly the Supertrak models).

we had a couple of Promise Supertraks in our FTP server, attached to ~1.2TB
of disk. we ran a RAID5 configuration, and they worked reasonably well for a
while...  but when a disk died, they didn't recover nicely. :( lost both
drive arrays and all the data on them.
fortunately it was just mirrors of numerous linux distributions; so they
were recoverable; but we wasted a heck of a lot of time working on the
things.

we replaced the Supertraks with a 12-port 3ware controller; and we've been
very happy with it. performs much better; and while replacing disks isn't
seamless, it *does* work, and the controller has a very good management
interface. (both a web-based interface to the monitoring daemon, and it will
send out e-mail alerts about its status).

the 3ware costs more ($600 for the 12-port); but it acutally *works*. :)

we only have it on a 32-bit PCI bus; so it won't perform as well as it would
on a 64-bit; but I think we got 70-80MB/s off it, when testing with
bonnie++. (well short of the 133MB/s theoretical limit; but still not bad.
maybe if we ran RAID0 rather than RAID5 it would be faster).

I don't know anything about the Fasttrak models; other than that they aren't
much better than software RAID. (considering that with a soldering iron and
a firmware upgrade you can convert one of their regular ATA controllers to a
Fasttrak, this means there really isn't much there but some glitz).
most cheap 'ATA RAID' controllers are the same way... nothing but firmware
and some fancy drivers.

Carl Soderstrom.
-- 
Systems Administrator
Real-Time Enterprises
www.real-time.com