Hard Disk Crash Recovery
In Linux you can use the dd command to copy MBR from one hard disk to another.
I currently use RAID1 with LVM on Fedora Core including RAID 1 on boot partition.
SystemRescueCd is a Linux system on a bootable CD-ROM for repairing your system and recovering your data after a crash.
Partimage is a Linux utility which saves partitions having a supported filesystems (see below) to an image file.
One of the main challenges of managing multiple dedicated web / database servers is the ability to centrally monitor and manage them, automate tasks which requires out-of-band access like rebooting the server or find out if the server is dying and arrange for replacement ahead of time etc.