Re: [tlug] auto-shutdown at certain temp, testing, and CF boot

[Walter Hansen <gandalf@example.com>]

Joe Larabell wrote:
> > ... I began by
> > setting up a raid 5 array on 3 SATA drives, then created the volume
> > group and creating the logical volumes for each mount point. However I
> > suddenly remembered that I did not have a spare IDE drive to install
> > the /boot partition into, and I needed all 3 SATAs for that raid5 array,
> > so I couldn't complete the install.
>
> I've never setup a raid 5 but I did set up a raid 1 once on matching
> partitions made up of exactly half of each of the drives on which the
> partitions were located. Assuming that works for raid 5 also, you might be
> able to slice off a few MB off the low end of one of the SATA disks for a
> boot partition. You may have to do the same for all three drives (raid 1,
> if I recall right, prefers identical partitions for the mirror -- raid 5
> may be more forgiving if the partitions sizes don't match). If you need
> identical partitions for the raid array, slice off the same size small
> partition from every disk and use the other two slices for something that
> doesn't require the redundancy of raid.
>
> BTW, you probably need a swap partition anyway. Use one of the three
> slices for swap, one for /boot, one for some other purpose and hook the
> remaining larger paritions on each of the three disks to the raid array.

This may go without saying and may not be relevant here, but I feel it's 
a good idea on a Raid 1 to mirror the boot partitions also. Also be sure 
to test the boot partitions on each disk by turning off the computer and 
disconnecting first one and then the other drive. You can always use a 
boot disk, but the idea is to come up 100% when one of the drives fail. 
I'm not sure how this applies to a Raid 5, but figured it was worth 
mentioning.