Resize Partition For RAID1

[BrainySmurf]

I found another hard disk in the scrap pile with no bad sectors that I wanted to use in RAID1 on my scrapyard computer. Since it's all used parts I thought this would make a great fail safe for the / partition. (/home is on another 30GB disk). They both say they're 40GB on the sticker but, according to gparted one is 38GB and the other is 37GB. The new disk I found is 37GB. My partitions are setup like:

CODE

Disk /dev/sdb: 30.8 GB, 30750031872 bytes 255 heads, 63 sectors/track, 3738 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x9ecf9ecf   Device Boot      Start         End      Blocks   Id  System /dev/sdb1               1        3739    30027776   83  Linux Disk /dev/sdc: 41.2 GB, 41174138880 bytes 255 heads, 63 sectors/track, 5005 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x4339a125   Device Boot      Start         End      Blocks   Id  System /dev/sdc1   *           1        4867    39086080   83  Linux /dev/sdc2            4867        5006     1121280   82  Linux swap / Solaris Disk /dev/sda: 40.0 GB, 40027029504 bytes 255 heads, 63 sectors/track, 4866 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xe258e258   Device Boot      Start         End      Blocks   Id  System /dev/sda1               1        4867    39087104   83  Linux

According to these instructions I need to run a command that maps the 37GB like the 38GB except that's not possible. I tried to shrink the size of the / partition on the 38GB to match the maximum size of the 37GB but they still aren't identical according to blocks they take up. Are those instructions even good? How would I resize my / partition to an exact size in blocks?

[AndrewSerk]

Hi BrainySmurf,
I like to use gparted for that kind of thing. It has a GUI and has worked well in the past for me.
http://koji.fedoraproject.org/koji/packageinfo?packageID=1950
http://distrowatch.com/table.php?distribution=gparted

Hope this helps,

[BrainySmurf]

QUOTE (AndrewSerk @ Apr 22 2012, 09:35 AM)

Hi BrainySmurf, I like to use gparted for that kind of thing. It has a GUI and has worked well in the past for me. http://koji.fedoraproject.org/koji/packageinfo?packageID=1950 http://distrowatch.com/table.php?distribution=gparted Hope this helps,

I did use the SL live cd's gparted. So, it's OK that for RAID1 the partition sizes aren't identical right down to the amount of blocks? I can proceed with the instructions listed?

I tried the instructions but I get stuck with this error message and I did use nodmraid in the kernel options.

CODE

[root@scrapyard rootl]# mdadm --verbose --create /dev/md0 --metadata=0.90 --level=1 --raid-devices=2 /dev/sdc1 missing mdadm: super0.90 cannot open /dev/sdc1: Device or resource busy mdadm: /dev/sdc1 is not suitable for this array. mdadm: create aborted [root@Daniel5 Daniel]#

[AndrewSerk]

Hi BrainySmurf,
Sorry for the belated response, the "disk utility" palimpsest can help build a raid array. The raid tool for palimpsest is under File in the palimpsest gui.
I will look through my notes for building a raid array after a install and post back what I find later tonight or tomorrow.

[AndrewSerk]

I went through my RHCSA and RHCE study guide for version 6x and there is nothing about creating a raid array after a install.
I know this was on the RHCE 5x exam but I have lent my notes and study guide to a friend and don't remember all the steps. ( To friend, If you read this today, look the info up and help out!) I will see my friend later this week and can go through the info I lent him and see what I can find.

There are a few guides online but they very greatly and I am not sure what one is correct.

[BrainySmurf]

QUOTE (AndrewSerk @ Apr 25 2012, 08:48 AM)

I went through my RHCSA and RHCE study guide for version 6x and there is nothing about creating a raid array after a install. I know this was on the RHCE 5x exam but I have lent my notes and study guide  to a friend and don't remember all the steps. ( To friend, If you read this today, look the info up and help out!) I will see my friend later this week and can go through the info I lent him and see what I can find. There are a few guides online but they very greatly and I am not sure what one is correct.

I actually reinstalled the OS and used the anaconda GUI raid setup. The GUI actually makes it as easy as doing something in Windows with no command line needed.

[AndrewSerk]

Hi BrainySmurf,

That is what I would have done also. I had looked through what info I had and couldn't find the proper info, but I forgot to post back. sorry for that!

Glad you where able to get things worked out.