Greetings, Wondering if anyone could assist with this. I have many SuperMicro 5015B-MTB servers. These all have the X7SBi Motherboards. After upgrading to CentOS 5.3 the Hard Drive LED's on some of the servers started blinking red(drive fail) but all is functioning normally. All servers are running raid 1 arrays with MDADM. Primary drive does not blink, but all others do including spares. These boards use the Intel ICH9R chipset. AHCI is enabled. When AHCI is disabled, drives stop blinking, but drives are then detected as hda,hdb,etc. and server takes a huge performance hit. All Servers have Western Digital SATAII 320G RE2 Drives. So far: I have reloaded Kernels Tried CentOS plus Kernels Flashed the Bios Replaced Backplane The funny thing is, not all servers are affected. If anyone has any ideas or could just point me in the right direction, it would be extremely appreciated. It's an annoyance more than anything else. Thx, ~Ron