[CentOS] 4 X 500 gb drives - best software raid config for a backup

[Jerry Franz]

dnk wrote:
> Hi there,
> 
> I am currently setting up a server that will house my backups (simply  
> using rsync).
> 
> This system has 4 X 500 gb drives and I am looking to raid for max  
> drive space and data safety. Performance is not so much a concern.
> 
> My experience with software raids in nil, so some of these may seem  
> like pretty dumb questions.
> 
> I was thinking a raid 1 is probably sufficient.
> 
> Would it be best to raid 1 two drives each and LVM them together?

The configuration you want is a hybrid of RAID1 and RAID5. The RAID1 is 
because GRUB doesn't grok RAID5, but is OK with just your /boot 
partition in RAID1.

Make a RAID1 for your /boot partition as follows:

/dev/md0 - /dev/sda1, /dev/sdb1, /dev/sdc1 (S), /dev/sdd1 (S) (100 Mbytes)


Make a RAID5 as follows for a LVM partition using the rest of your 
available space as follows (just under 1500 Mbytes):

/dev/md1 - /dev/sda2, /dev/sdb2, /dev/sdc2, /dev/sdd2

Create a LVM partition on /dev/md1 and carve out your / and swap 
partitions from it.

> My next question would be about how to do this as I have never done a  
> linux software raid.

-- 
Benjamin Franz