howto add additional sas harddisk on existing RAID5 system

taboo · 10-19-2007, 09:55 AM

Hi friends, im running centOS4, with 3x147GB SAS HD on RAID5. This is my /etc/fstab content:

/dev/VolGroup00/LogVol00 / ext3 defaults,usrquota,grpquota 1 1
LABEL=/boot /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /dev/shm tmpfs defaults 0 0
none /proc proc defaults 0 0
none /sys sysfs defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
/dev/hda /media/cdrecorder auto pamconsole,exec,noauto,managed 0 0

$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
278704192 209407276 55139504 80% /
/dev/sda1 101086 39802 56065 42% /boot
none 4155264 0 4155264 0% /dev/shm

Since / partition is almost full im planning to add 300GB SAS HD. How would it be? Any recommendation or howtos? Thanks...

acid_kewpie · 10-21-2007, 03:12 AM

you can't expand a raid5 array once created, and you certainly can't add a drive of a totally different size. you would probably want to identify a section of the current partition, possibly /usr or /home which you can migrate off of the raid5 onto a totally isolated bit of storage.

taboo · 10-24-2007, 05:44 PM

thanks for your reply acid_kewpie

just want to ask about LVM, i would like to expand my VolGroup00. when i expand it to another PV is the data on VolGroup00 intact and safe? Do i have to format first the new PV before the expansion occur? thanks...