RAID Level 1 and 5

Hi_This_is_Dev · 10-07-2009, 06:50 AM

First, RAID1 was implemented and it worked. Then the partitions sda6 and sda7 were deleted and sda6, sda7, and sda8 were created for a fresh implementation of RAID Level 5.

I stopped the existing RAID:

Code:

[root@localhost ~]# mdadm -S /dev/md0
mdadm: stopped /dev/md0

This is the scene after deleting the partitions and recreating them:

Code:

[root@localhost ~]# fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        1275    10241406   83  Linux
/dev/sda2            1276        1657     3068415   82  Linux swap / Solaris
/dev/sda3            1658        2874     9775552+   5  Extended
/dev/sda5            1658        1901     1959898+  83  Linux
/dev/sda6            1902        1914      104391   fd  Linux raid autodetect
/dev/sda7            1915        1927      104391   fd  Linux raid autodetect
/dev/sda8            1928        1940      104391   fd  Linux raid autodetect

Disk /dev/md0: 213 MB, 213647360 bytes
2 heads, 4 sectors/track, 52160 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md0 doesn't contain a valid partition table
[root@localhost ~]#

The underlined line above states some error or warning. Why is it there?

I have been told by my trainer that now I must create other partitions, sda9, sda10, sda11 for the new RAID because the previous one is creating the problem. I am trying that now, however, I want to know why we have to leave sda6 and sda7 even after deleting them.

Well, here is what I am trying now:

never say never · 10-07-2009, 08:59 AM

Did you remove the partitions from the array? ie:

mdadm --manage /dev/md0 --remove /dev/sda6
mdadm --manage /dev/md0 --remove /dev/sda7

Once that is done you should be able to assign them to the new Raid 5

I think you got the following:

Disk /dev/md0 doesn't contain a valid partition table

because the array is still configured, but the partitions were destroyed and recreated, so the md0 partition data no longer exists for the array.