Oh well. Short power failure killed nodes n0001-n0004. n0002 upon reboot 'lost' two cores (bloody BIOS update to 3.1 and bloody 'green' UPS's). Decided to try my luck remotely via flashbios hoping to go back to BIOS v.1.4. Unfortunately, but not unexpectedly, this didn't work as expected, especially when considering that I used a BIOS dump of a different node. After a short trip to access the cluster physically, and a few problems with MAC addresses, n0002 is up again, but still on BIOS v.3.1. Damn …