[mythtvnz] partitions

[Sam Hadley-Jones]

While on the subject of drives and partitions, has anyone looked into
striping together a bunch of USB flash drives? My current setup is 5x500GB
WD GP drives in RAID5+LVM for movies and recordings and a 250GB drive for
OS, swap and torrents. The 250GB drive never gets more than 20GB used and I
don't really need the swap space at all with 2GB of RAM. The RAID array
spins down after 20 minutes of inactivity using the spindown utility. This
is a good power saver of about 25W for most of the time but does present an
annoying problem - when you want to watch live TV after the array has spun
down, it needs around 8 seconds to spin up and will usually fail to start
live TV a couple of times for those impatiently repeatedly pressing the
button. What's needed is better access time.

I was thinking that since solid state drives are still relatively
expensive, I could stripe together 4x 8GB usb sticks on a hub and allocate
8GB for OS, 8GB for torrents and 16GB for live TV. The aggregate bandwidth
of the USB RAID array should be plenty for live TV and the OS. Plus, I'm
hoping that channel changing will be a bit snappier with the better access
times of flash.  Wear on the flash memory shouldn't really be a problem for
live TV since it would probably take a week to write over the full 16GB
space allocated. These flash drives usually state a life of 100,000 writes
resulting in around 2000 years of average TV viewing. I understand that
/var will have to be mounted on tmpfs. Is there anything else I need to be
aware of with this setup? Has someone else here done something similar?

I'm also looking for a better solution other than LVM for my main RAID
array. LVM puts too much of a performance hit on the system - I usually get
around 50MB/s sustained! I do like the feature of being able to make
read-only snapshots for online automated fscking of LVM volumes. It also
makes migrating drives a lot easier. I've been watching the development of
ext4 and btrfs as a replacement but I don't know whether they're proven
reliable yet.

Sam.