[CentOS] RAID, LVM, extra disks...

Thu Nov 29 05:59:38 UTC 2007
Ugo Bellavance <ugob at lubik.ca>

Hi,

	This is my current config:

/dev/md0 -> 200 MB -> sda1 + sdd1 -> /boot
/dev/md1 ->  36 GB -> sda2 + sdd2 -> form VolGroup00 with md2
/dev/md2 ->  18 GB -> sdb1 + sde1 -> form VolGroup00 with md1

sda,sdd -> 36 GB 10k SCSI HDDs
sdb,sde -> 18 GB 10k SCSI HDDs

I have added 2 36 GB 10K SCSI drives in it, they are detected as sdc and 
sdf.

What should I do if I want to optimize disk space?

The simplest solution would be to create /dev/md3 out of sdc1 and sdf1, 
and add it to the VG, and increase the size of my /vz logical volume.

However, if I could convert that to a RAID5 (it could be possible to 
re-install, but I would rather not), I could have 6 drives in RAID5, so 
I'd have 5x36 GB (180) of space available total, instead of 3*36 (108).

Also, please note that this is a Dual PIII 1.2 Tualatin. I'm runing 
OpenVZ with virtual machines that are not really CPU expensive, but I 
would not like to see my processors spending most of their time 
computing XORs for the RAID5.

Any suggestions/tips welcome.

Regards,

Ugo