[Bassetlug mailing] Setting up RAID

[MJ.Wells]

Good to see 'old' and 'new' members at the meeting last evening where Philip
gave us a very informative demonstration of setting up RAID in Ubuntu.

Philip told us that he had occasionally seen problems when he set up some
systems which he felt were due to not having identical drives in the array
as is recommended. 

Philip then showed us that  setting up the RAID in the BIOS causes Linux to
be unable to find the boot loader so that the most expensive of equipment
just loops at boot as it could save me much time in the future. It seems
that the boot partition has to be excluded from RAID.

Philip went on to explain the difference between RAID 0 (striped) and RAID 1
(mirrored) along with the more complex RAID 10 (1+0) which combines both.
After a detailed setup of the partitions using the hardware RAID which led
to the failure to boot, Philip showed us the process of setting up the
drives in the Ubuntu Server install. Finally we looked at leaving the setup
of the RAID until Ubuntu had been fully loaded on some of the disks.

Unfortunately, even though we extended our evening until well past 10pm as
we were enjoying the demonstration so much, we had to leave the full use of
mdadm until another time.

I have not encountered this technology before and have learned a lot. Thanks
Philip for a very informative and useful demonstration. Now ... I wonder
where can I lay my hands on four unwanted 500Gb-ish drives so that I can try
it all for myself?

Martin