[CentOS] preferred software RAID 10?

>/boot shouldn't be mirrored, as the BIOS won't know how to boot it.

Not true for all mobo's. Regardless, why not have a copy safe somewhere
easier to manage then the following suggestion IMHO. Let the computer
worry about remembering to copy it.

>leave /dev/sdb1 the same size as /dev/sda1 and call it /boot2 and try to
>remember to copy /boot to /boot2 each time you update the kernel.