raid + lvm setup

[Douglas Tutty <dtutty@porchlight.ca>]

I'm going to be reinstalling my amd64 using Etch RC1 in an effort to
track down bug 402157 re grub not installing.

This gives me the opportunity to rearrange how the drives are set up.

I have two Seagate Barracuda 80 GB SATA-3.0 drives.

Right now (running amd64 Etch pre RC1), I have both drives partitioned
the same:
	1	64 MB		raid1 	md0 	/boot
	2	remainder	raid1	md1	pv0 vg0 for LVs

Then LVs for everything including swap.

I did this to avoid a reinstall if a drive fails.  However, I only need
to protect the base system in this way; I keep good backups of
everything else.

I'm wondering about doing this with the next install:

	1	64 MB		raid1	md0	/boot
	2	20 GB		raid1	md1	pv0 vg0 for LVs
	3	remainder:
			as separate pv1 and pv2 in vg1 for LVs

Then in vg1 I can have LV vg1-home and later when I get into video
editing, if I need it for performance, I can make a striped LV
vg1-editing and mount that wherever the video editing software wants it.

I'll put /tmp on tmpfs with lots of swap (in the raid1-protected vg0).

I want the swap to be encrypted.  I don't want to have to enter a
passphrase on boot; if I want to create or download a file that I want
encrypted I can do that onto /tmp then encrypt the file before moving it
off /tmp.

This leaves the base system protected by raid1, gives twice the space
for /home, and the possibility of a striped editing volume.

Does this seem like a workable/wise plan or here there be dragons?  Is
there any reason to think that 20 GB is too small for a fully installed
workstation including swap and /tmp (everything but /home)?

Thanks,

Doug.