I recently updated two 64-bit CentOS 5.3 systems via yum update. - One system had two physical SATA hard drives - drive 0 was Windows XP w/SP3 w/NTFS, drive 1 was CentOS; - The other system had two physical SATA hard drives, configured via a hardware mirror of RAID 1 (mirroring) After the latest yum update, grub on both systems failed me, dropping to the grub prompt. For the dual-boot system, I ended up reformatting and reinstalling Windows on drive 0. The CentOS was not touched. That system is fine now. For the RAID CentOS-only system, I experimented with removing one drive from the mirror and CentOS booted as though it was reboot after a fresh install, though there were some traces that something else (like an upgrade) was mixed in, but didn't work right. I ended up deleting the hardware RAID and removed a drive. That system works fine now. Has anyone else experienced grub problems with more than one drive installed from a recent yum update? I will not perform an update on any other multi-drive systems, including servers, until I know things are fixed. Thanks for any insights. Scott