Promise SATA 300 TX4 Problem

[Mark Murawski]

I'm having drive problems with my sata controller.  I've seen something 
very similar to this bug reported in the way back:

http://forums.freebsd.org/showthread.php?t=17642
http://lists.freebsd.org/pipermail/freebsd-stable/2011-April/062428.html

It's not a hardware problem.  The same hardware running linux has no 
problems at all (same hard drives, sata cables, promise board and 
everything)

Usually during zfs resilvering I'll see something like this.

ata2: timeout waiting to issue command
ata2: error issuing ATA_IDENTIFY command
ata2: SIGNATURE: ffffffff
ata2: timeout waiting to issue command
ata2: error issuing ATA_IDENTIFY command
ata2: SIGNATURE: ffffffff

I have 5 mirrors in a zfs pool.  Throughout the day, one drive in each 
mirror, one by one will drop out with those errors, and eventually get 
removed from the pool. Rebooting "fixes" the problem until the drives 
start timing out again.