[ltp] raid1 on thinkpad A31

[Jon]

> I just learned how to run a full system on Linux software
> RAID1 and would like to do this with my Linux Thinkpad.
> (i.e. root on raid1)

Thumbs up. I use software RAID-1 at home, on a server though, not a
laptop. All partitions mirrored, boots off either drive. Sweet.


> For a proper RAID1 mirror, it is best to have the 2 drives
> on different controllers.  If they are both on the same
> controller, and that controller dies, you can't boot.

I wouldn't worry about this. If the controller dies, likely something else
has happened that would stop you using it anyway, eg. you dropped it in a
swimming pool.

The main consideration is to use separate channels on a controller. Using
hda and hdb is no good because that's master/slave and only one can use
the bus at a time. It's MUCH slower, from my experience. So hdc for the
2nd drive is good.

The good thing about software RAID is that you can easily access the data
if something goes wrong, because you know what format its in, ie. just
regular linux partitions. So even if you can't boot because of a broken
controller, you can still stick one disc into another machine and get at
your data easily. Which is the main thing I guess.


> Are hda, hdb, and hdc all on the same controller?

Yeah.


> Any other comments on my Thinkpad RAID1 project are welcome.

None of my business but how necessary is it?! ;-)


Jon.