What is considered "the best supported" RAID controller for 5.x?

[Douglas K. Rand]

JM> Basicly a process will hang in either ffsfsn (fsync induces this
JM> write) or getblk (a read), and as far as I can find out, the io
JM> just never returns even though the underlying block device
JM> continues to work fine..

I know this is probably a stupid answer, but ...  Have you upgraded
the firmware on the card? We have a number of ICP cards and with the
2.39 firmware we can easily lockup the box with the behavior you
explain with a simple buildworld.  Upgrading the firmware to 2.44
solves the problem completely for us.