About 9 months ago, I made a policy decision to adopt RAID 1 on all systems I admin. (about 20 systems, all told) It's been a long, slow process. One of the systems is being upgraded from CentOS3 to CentOS4. It's been rock-solid stable for over a year. It's a "frankenserver" with parts from all over the place, maintained over years of active service. Currently, it's got an ASRock "M810LMR" motherboard in it. http://www.ciao.co.uk/ASRock_M810LMR__5410842 When I install the O/S (I've tried CentOS 4.0 and 4.2) with IDE RAID, it bombs, takes hours just to format the drives, and won't reboot, getting stuck at "GRUB". But, when I install the SAME TWO DRIVES without RAID, (eg: some partitions on one drive, some on the other) it works perfectly. I've tried putting both drives on separate IDE cablels, using completely different drives, and trying CentOS 4.0 and 4.2. When I try to set up IDE raid while it's taking a very long time to format the drives, I see lots of errors about DMA on the alternate consoles, and there being only one drive (unable to start RAID array, only 1 drive found) even though the installer and disk druid have no problem reporting both drives. It comes down to something like "/dev/mdN delayed until /dev/mdX is synchronized because they share physical resources"... I'm stumped, and falling back to non-RAID because this system is needed in production. And, I'm not new to using software RAID, I've been using it for years without issue. Any idea what's going on? -- "The best way to predict the future is to invent it." - XEROX PARC slogan, circa 1978