[ Thanks to finid
for this link. ]
“The most common practice is to dual-boot on a computer with one
hard drive. That, however, gives the system a single point of
failure. If you can afford to, the best option, especially on
server installations, is to install each operating system on a
separate hard drive. That ensures that if something goes wrong with
one OS or one hard drive, you can always boot from the other drive,
and troubleshoot the other one whenever you are ready. That is tip
number one for dual-booting your favorite Linux distribution and
Windows.”