Purpose of RAID
Improve read/write performance and ensure redundancy in case of a hard disk failure.
RAID levels
Raid levels can be known in detail from wikipedia http://en.wikipedia.org/wiki/RAID
/proc/mdstat
cat /proc/mdstat
If there are any RAID devices present, they will be shown in the terminal…like this
md2 : active raid1 sda4[0] sdb4[1]
md1 is a RAID 1 (mirror) device, spanning sda4 and sdb4 partitions. This device is active and mounted. If it were not used, it would have been listed under unused devices further below.
458111864 blocks super 1.2 [2/2] [UU]
[2/2] [UU ] – tells us both partitions are used.
if it appears like this [1/2] or [U_] then you have a degraded RAID array.
Do manual partition and make partitions as per you need
edit partitions and select use as physical volume for raid
repeat this for all partitions and make all partitions physical volume for raid
Then select Configure Software Raid
Then select write changes to disk if correct
the next step is to create a new MD device.Choose Create MD device
Then choose the raid type you want
Choose no of devices
need to decide how many (active) devices will participate in the mirror.here its two
The next step is to choose spares here its zero
Next choose devices we need to select which devices we want to use. For the first device, we’ll use sda1 and sdb1.
repeat the procedure for the other two devices
Now select root ,swap and home partitions….
Then installation begins………….
After installation boot up to your system open terminal and type
cat /proc/mdstat