Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have ESXi 4 on a home-built server with a 925GB RAID5 array (adaptec 2405 card) with a single Centos5.4 VM running on it. The VM has a provisioned size of 20GB which I can't seem to increase using the vSphere client. Now I would like to either increase the size of the Centos VM to use more of the free space or I would like to somehow use the datastore as another volume that can be easily accessed from the Centos VM. Does anyone know how to achieve this? Thanks.

share|improve this question
up vote 3 down vote accepted

What have you tried from the vSphere client?

Is the virtual machine powered off? Are there any snapshots on the virtual machine?

The machine needs to be powered off and without snapshots before resizing the drive. After you resize the virtual disk you can use gParted and/or LVM tools to resize the partition.

share|improve this answer
All good ideas Andy, I think both you and I have had training and/or read the manual. Fingers-crossed Ben gives this a go soon ;) – Chopper3 Nov 1 '10 at 16:52
Hi, sorry for the slight delay. Been looking through the vsphere client manual but still can't find any instructions on how to resize a VM (..bearing in mind it is already THICKLY provisioned). I did find out that I can add a new virtual HDD looks like the only solution....unless I missed something. – Xoundboy Nov 3 '10 at 17:19
Make sure the VM meets the requirements in the above posted answer. Right click and go to 'Edit Settings'. Select the virtual disk that you want to resize. On the right side, you should be able to type in a new size in GB. This will resize the virtual drive... but not the partition that the operating system uses. – andyhky Nov 3 '10 at 17:27
As it turned out the block size of 4MB limited the maximum size of a virtual disk to 256GB which wasn't big enough and rather than re-building the datastore with a larger block size I decided to create a set of three new virtual disks which I then used to make a new LVM volume group etc. I blogged this in my blog here: – Xoundboy Nov 19 '10 at 13:18

You could also create a new vmdk file with the desired size and add it to your CentOS VM as another drive.

share|improve this answer
yes, this is probably the easiest route I reckon, thanks. – Xoundboy Nov 3 '10 at 17:20

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.