Monday, January 26, 2009

Adding disk space to a Linux VM in VMWare - Take 2

A little while back Frank posted a blog about increasing the size of a logical volume in Linux ( I tried this out and it worked great.

I also had to do something similar in Windows, which turns out to be much simpler by using the VMWare Converter. Unfortunately this is not supported for Linux. The one thing that got me thinking though is that Windows can increase from a single drive and not have to use a separate drive. So why could I not do this in Linux?

The reason I needed to do this was for the new version of TPM (7.1). I originally had my VM set up with 20GB allocated, but the new version now requires approximately 50Gb to install, so the steps below are what I used to increase the LVM for my TPM install.

Here is my setup:
VM Ware: VMWare Server 2.0.0
Host OS: Windows 2003 SE SP2 x64
Guest OS: Red Hat ES4 U5

Increase VM Disk Size
Use the VMWare tool vmware-vdiskmanager.exe to increase the size

C:\Program Files (x86)\VMware\VMware Server>vmware-vdiskmanager.exe -x 50GB "f:\
VM_Images\VM TPM7.1 RH\rhes4srv01\Red Hat Enterprise Linux 4.vmdk"
Disk expansion completed successfully.

Use fdisk to create new partition
Even though the previous step reports that more disk was added, it still is not recognized by the OS.

Current file system:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 19448516 1964128 16496436 11% /
/dev/sda1 101086 13232 82635 14% /boot
none 257208 0 257208 0% /dev/shm

1. Enter the FDISK utility
fdisk /dev/sda

2. Print the existing partition table
Command (m for help): p

Disk /dev/sda: 53.6 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2610 20860402+ 8e Linux LVM

3. Create new partition. This will be a Primary partition and is the 3rd partition. For the cylimder values, press enter to accept the defaults

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 3
First cylinder (2611-6527, default 2611):
Using default value 2611
Last cylinder or +size or +sizeM or +sizeK (2611-6527, default 6527):
Using default value 6527

4. Set the Partition type to Linux LVM (hex 8e)
Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): 8e
Changed system type of partition 3 to 8e (Linux LVM)

5. Print the Partition table again to see the new partition
Command (m for help): p

Disk /dev/sda: 53.6 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2610 20860402+ 8e Linux LVM
/dev/sda3 2611 6527 31463302+ 8e Linux LVM

6. Write the new partition information
Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

7. Reboot

Create the Logical Volume
Now that the partition is created, the physical and logical volume needs to be created

1. Create the Physical Volume - use the new partition information from the df command. In this case the new partition is /dev/sda3
pvcreate /dev/sda3
Physical volume "/dev/sda3" successfully created

2. Add the new Physical Volume to the Logical Volume
vgextend VolGroup00 /dev/sda3
Volume group "VolGroup00" successfully extended

3. Extend the Logical Volume.

--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 49.88 GB
PE Size 32.00 MB
Total PE 1596
Alloc PE / Size 635 / 19.84 GB
Free PE / Size 961 / 30.03 GB
VG UUID bzOq45-o5yO-ruYY-Ffx1-DxCx-2e2j-ardXtu

lvextend -L +30.03G /dev/VolGroup00/LogVol00
Rounding up size to full physical extent 30.03 GB
Extending logical volume LogVol00 to 48.88 GB
Logical volume LogVol00 successfully resized

Note: The lvextend can either use the value of the Free PE from the vgdisplay command or the command lvextend -l +100%FREE /dev/VolGroup00/LogVol00. I found out about the %FREE after, so I did not test this.

4. Extend the filesystem
The resize2fs does not work for this situation. The command ext2online will allow for the disk to be resized while disk is still mounted.

ext2online /dev/VolGroup00/LogVol00

5. View the new file system
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 50444996 1972848 45911716 5% /
/dev/sda1 101086 13232 82635 14% /boot
none 1825828 0 1825828 0% /dev/shm

And there is a system with a nice large drive. Hope this helps you.


Wanderer said...

Thanks for sharing. I have the need to do this tonight and found your posting...

Martin Carnegie said...

Good to hear this was useful. Let me know if this worked for you or if you had to modify any of the instructions.


Jason Chiu said...

Thanks for the information. It works for me on Oracel Enterprise Linux 5. Need to use resize2fs instead of ext2oline though.

Yinal Ozkan said...

This is the only advice that worked on "How to extend LVM partition" Now my VM images have room to breath...thanks.

Martin Carnegie said...

Hi Jason,

Thanks for the feedback on the RH 5. I have not tried that version yet, so this is good to know.

Thierry T said...

Great post. Actually I used it twice on a system that we had troubles estimating the needed space.

What should be done with fdisk when 4 primary partitions have been used?


pravms said...

Thanks a lot... Well written manual!!!
Every step executed perfect.
Just one additional note: centos 5 has replaced the command 'ext2online' with 'resize2fs', but the functionality and parameter is the same.


Endless days said...

Thanks for sharing this. It worked on RHEL5
I used this:
lvextend -l +100%FREE /dev/VolGroup00/LogVol00

Best Regards,

Laura said...

Worked like a charm for Linux RedHat Enterprise 5.0 (with the tweak recommended for the Oracle version earlier in the comments).

Thank you so much!

Martin Carnegie said...

Glad to see that this is still helping. Thanks all for the comments and modifications to make this work in the newer releases.