how to mount SAN volume with its increased volume size

prvnrk · 03-21-2008, 01:31 PM

Hi,

We have 200GB SAN volume mounted on Redhat EL 5. which is working fine. Then i resized the SAN Volume to 300 GB (after unmounting from the server)and remounted, it shows 200GB only but data is intact.

Now, my requirement is to let Linux see whole 300GB and be able to mount full 300GB along with data.

Pl advise.

Thanks
Prvn

trickykid · 03-21-2008, 04:29 PM

What does fdisk display for the size? What filesystem are you using? Are you using LVM at all?

From my experience you need to use fdisk to resize the LUN. As long as you don't wipe the whole disk, the data should stay intact. But you should always have backups just in case when doing these types of things.

Once you make your changes with fdisk, you probably need to use resize2fs or equivalent to tell the OS the new size of the LUN. Might want to run e2fsck -f <device> as well.

prvnrk · 03-21-2008, 04:50 PM

Quote:

Originally Posted by trickykid

What does fdisk display for the size? What filesystem are you using? Are you using LVM at all?

From my experience you need to use fdisk to resize the LUN. As long as you don't wipe the whole disk, the data should stay intact. But you should always have backups just in case when doing these types of things.

Once you make your changes with fdisk, you probably need to use resize2fs or equivalent to tell the OS the new size of the LUN. Might want to run e2fsck -f <device> as well.

Hi,

Thank you for your response.

fdisk displays old size (200GB) only. We are using ext3fs and not using LVM at all.

But i'm not very sure what exactly needs to be done using "fdisk". Do the e2fsck and resize2fs work for ext3 file systems?

Could you please provide me more details on using fdisk for resizing the LUN and other commands?

Thanks much
Prvn

trickykid · 03-21-2008, 05:08 PM

So when you did a fdisk -l you didn't notice that the size of the disk has changed but not the size of the partition? Compare the size of the cylinders with the disk compared to the device listed and see if they don't match up. If not, you need to do something like this:

Code:

fdisk <device>
<other lines ommitted here>
Command (m for help): d
Partition number (1-4): 1
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
<you'll see some stuff about using default value and it's cylinder size here>

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
   <some lines omitted>
Syncing disks.

From that point on, remount, it might still display the old size in a df output. You may need to restart the system or rescan your scsi/LUN's. Once you've done that, run the e2fsck and the resize commands so it starts using the extra added space.

prvnrk · 03-22-2008, 10:48 AM

Thank you trickykid,

It worked great!

Thanks again
Prvn