John R Pierce wrote:
Johnny Hughes wrote:
The easiest way to make that happen is to use a product called DRBD
do be aware, drbd replicas are not 'safe' for things like transactional databases, unless they are configured to be synchronous (such that a fsync doesn't return until its written on both the local disk AND the replica), which slows everything way down.
If you can tolerate a small amount of downtime, a more simple-minded approach is to get servers with swappable drive carriers, set up your production servers with all partitions on raid1, and keep a spare similar chassis around. Then if a single drive dies (the most likely failure), you just swap in a new one and resync the mirrors. If the motherboard or power supply dies, you swap the drives into the spare and come up in the time it takes to reboot (you'll probably have to fix the NIC setup for the different hardware addresses, though.).