RAID (Redundant Array of Inexpensive Disks)
Create 3 partitions for implementing RAID using fdisk command.
e.g. #fdisk /dev/hda
Press n to create the 3 new partitions each of 100Mb in size.
Press p to see the partition table.
Press t to change the partition id of all the three partitions created by you to fd (linux raid auto).
Press wq to save and exit from fdisk utility in linux.
#partprobe
Use fdisk -l to list the partition table.
Creating RAID
# mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/hda6 /dev/hda7 /dev/hda8
Press y to create the arrays.
To see the details of raid use the following command: -
# cat /proc/mdstat
# mdadm --detail /dev/md0
Creating the file system for your RAID devices
#mkfs.ext3 /dev/md0
Mounting the RAID partition
#mkdir data
# mount /dev/md0 data
#df -h /root/data (Command is used to see the space allocation).
Crashing the raid devices
# mdadm --manage /dev/md0 --fail /dev/hda8
Removing raid devices
# mdadm --manage /dev/md0 --remove /dev/hda8
Adding raid devices
# mdadm --manage /dev/md0 --add /dev/hda8
View failed and working raid devices
# cat /proc/mdstat
# mdadm --detail /dev/md0
# tail /var/log/messages
To remove the RAID follow these steps: -
1) unmount the mounted directory where raid is mounted.
e.g. umount data
2) Stop the device
e.g. mdadm --stop /dev/md0
3) View the details of your raid level using following command: -
#cat /proc/mdstat
#mdadm --detail /dev/md0
