[mythtv-users] Question re: available SATA ports and linux software RAID

[Alex Butcher]

On Tue, 12 Apr 2011, Simon Hobson wrote:

> Don't forget that you don't have to do the same thing (ie one big
> array) with the whole drive. You can partition the disks, and then
> built arrays with the partitions (as mentioned before). So you could
> have a small boot volume that's mirrored across all the drives, a
> system volume that's RAID6 across all the drives, and separate
> unraided drives for Myth storage. Just for example.

I do exactly this. In the past, I've even had - on the same pair of discs -
a RAID1 array for important stuff and a RAID0 array for unimportant stuff
where extra IO performance would be handy (e.g. /usr/src/, /tmp).

On my current MythTV FE/BE with 2x2TB HDDs, I have:

a 2GB RAID1 array for /boot

a 430GB RAID1 array currently containing:
- a 20GB LVM LV for the OS
- a 5GB LV for /home
- a 90GB LV for emulator ROMs
- a 60GB LV for MP3s
- a 10GB LV for /var (including /var/lib/mysql)
- a 2GB LV for /var/spool

a 1.04TB RAID1 array currently containing:
- 5 213GB LVs configured as my default storage group (I use jfs, which can
   only be expanded - this config allows me to free up an LV and repurpose it
   if necessary, without having to backup/mkfs/restore what remains of the
   entire 1TB filesystem)

2x350GB LVM PVs (unRAIDed) containing relatively unimportant stuff:
- 2x210GB LVs configured as my 'filler' storage group
- a 105GB LV for videos
- a 135GB LV for downloads/local mirror of yum repos
- a 25GB LV for /tmp
- a 5GB LV for /var/cache
- a 1GB LV for /var/tmp

2x2GB of swap (yes, if a disc dies, the machine will probably crash. If I
wanted to prevent this, I'd put swap on another RAID1 array).

Best Regards,
Alex