monline

A nice, detailed howto. It's in the Ubuntu forums, but it does not contain anything Ubuntu specific (ie. you can use it with any distribution).

The essential information -that I lacked- was here: "Avoid Reboot after Partition Change with Fdisk". I've found references to the /sys/block/sda/device/rescan Sysfs entry too, but it seemed not to help. The partprobe command on the other hand worked like a charm.

This is something very much not trivial. Let's assume you've two (or more) disks. You create a partition with the same size on each and create a RAID volume from them. You create an LVM volume group on this RAID volume and create one (or more) logical volume(s) in it. The point is that you have the "/boot" directory in a logical volume in the RAID volume and boot the system from it.

This is again a script that people could write easily if they understood some shell scripting, but it is quite well implemented with logging and all and maybe spares a couple of minutes/hours of your time.

You should use it with crontab on a daily basis. For details take a look at the desc. of the MySQL backup script.