We have encountered an issue with our SCA6000 card's kernel driver in RHEL 5.5. It seems that occasionally, in some (yet unknown) circumstances the card's kernel driver stalls and rebooting the server seems to be the only way to get the driver working again. The following syslog entries can be seen after the driver crash:
We suspect that this is somehow related to the SCA6000 Linux driver and how it works in an SMP environment. As a workaround, we have disabled multiprocessing in our server by setting maxcpus=1 in our GRUB configuration. So far the issue hasn't re-occurred, but it's not sure whether this workaround helps or not, because the issue has occurred earlier very rarely.