Raid5
 

Hello,

I am trying to setup a test RAID5 and i'm using three partitions(5,6,7) of the same disk...(2 of 500M and 1 300M). After setting them up as Linux raid autodetect with fdisk(rebooted as well), i try to run mkraid /dev/md0, (made proper entries in /etc/raidtab) but it shows me that "/dev/hda5 appears to contain an ext2 filesystem, use -f to override." I have tried to delete the partitions and then recreated them also and i didn't even format them with ext or ext3...but it shows me the same message :confused: :confused:

Please help..

PS : when i tried using mkraid -f /dev/md0 it gave me a warning page and then i tried -R it removed the data but then again reconstructed it...

To get RAID5 working you will need a minimum of 3 DISKS with 1 "Linux Raid" (type fd) partition per disk.

When you have got another 2 disks you should be able to use the 'mkraid /dev/md0' command to get it to work.

use mdadm,Its a bit easier.
mdadm -C /dev/md0 -c32 -l5 -p left-symmetric -n3 -x1 /dev/sd{a,b,c,d}3

in the above;
-C creates the array
-c32 is blocks...32 is about default for avg use in raid 5
-l is the raid level raid 5 l5
-p can be left out as mdadm uses left-symmetric by default with raid 5
-n is number of disks in array
-x is spare disks...use if you have 4 or more and want a lil more redundancey...leave out in your case

In my case I had 4 disks and wanted all the disks 3rd partition raided....so for sda3 sdb3 sdc3 sdd3 I do /dev/sd{a,b,c,d}3

in your case /dev/hda5,6,7

More tools in mdadm to work with your array as well.


If there was a previous array you must zero the partition
Id zero it anyway.