[CentOS] New install RAID 1+0

Thu Nov 19 18:47:10 UTC 2009
Ron Loftin <reloftin at twcny.rr.com>

On Thu, 2009-11-19 at 11:30 -0700, Craig White wrote:
> I have a new server to setup. 4 hard drives and I had intended it to be
> hardware raid but that's a long story.
> 
> Does it make sense to set up the first two hard drives with RAID-0
> partitions and then get through the install and then go back later and
> then create identically sized RAID-0 partitions on the other two drives
> and finally create the RAID-1 mirror from the first to the second?

I suggest that you consider LVM over RAID 1.

Since you have 4 disks, I would make a small RAID 1 on your first two
disks ( or if you are using IDE disks, the primary and secondary
masters ) to be /boot ( GRUB doesn't work with booting directly from
LVM ) and then create one or more RAID 1 devices in the remaining space.
You then use the RAID 1 devices as physical volumes in the LVM setup,
and create logical volumes however you wish.

My own "personal opinion" is that I use one RAID 1 device to support a
volume group that I call "sysdisk" and use for "system" filesystems such
as /, /var, /tmp, and swap.  I use any additional RAID 1 devices in a
volume group I call "export" and put all of my data ( home directories,
downloaded audio/visual media, ISO images, etc. ) in logical
volumes/filesystems there.

One of the benefits of LVM is that you can have more than one physical
volume ( PV ) in a volume group, which will let you construct logical
volumes ( LV ) that are larger than your hard disks.  You can also
resize LVs/filesystems and do some other useful things.

My $0.02 (US) worth.

> 
> Craig
> 
> 
-- 
Ron Loftin                      reloftin at twcny.rr.com

"God, root, what is difference ?"       Piter from UserFriendly