VMware ESX vSphere resize disk
Every now and then I need to resize (usually extend/enlarge) a disk attached to a Virtual Machine. I have tried several methods to do this over the years (including combinations of VMware Converter, third party partition manager apps, diskpart etc) but none have been as efficient as the method I discovered during recent VMware training for my VCP4 exam.
One of the new features of vSphere is the ability to resize disks without having to shut down the Virtual Machine. This was previously impossible in VI3. This greatly speeds up the resizing process which can be executed in a couple of stages:
1) Use the vSphere Client to edit the settings of the Virtual Machine in question. Select the hard disk and modify it's provisioned size as appropriate. Click OK to apply these changes - resizing the .vmdk file.
2) Verify that the .vmdk has been resized by opening the Management Console -> Disk Management to find the unallocated space on the disk that resides in the .vmdk (distinguished by the black colour in the legend at the bottom.) In this case you can see I have increased the size by 5GB.
Right click on the disk (in this case 'Disk 0') and select properties. On the Volumes tab make a note of the unallocated space, in my case it is 5122MB.
If you are using Windows Server 2003 or earlier versions of Windows (Note: Windows Server 2008 now allows you to resize a disk through Disk Management in the Computer Management Console/Server Manager even if this disk is the Boot/Page File disk) download Dell's EXTPART and extract it on the server that contains the disk you want to resize. Navigate to c:\dell\ExtPart (the default extracted location) and run extpart.exe. When prompted enter the the Windows drive letter of the disk on the Virtual Machine e.g. c:. When prompted for the size to extend the partition by enter the number noted down earlier (I used 5122 in this example.) After doing so the disk should be resized. You can check this by opening the Management Console -> Disk Management and verifying the size of the partition.
NB - If you receive the following error:
"Unable to connect to c: or it does not exist"
There are a couple of workarounds that you could try.
1) Close the Management Console (if it is open) and try extpart.exe again.
2) Try restarting the VM in safe mode and then run extpart.exe. This is not ideal but it is still easier than other methods I have tried to resize .vmdk files.
I was excited when reading this as I have been looking for an easy way to do this for a while.
However, when attempting to use the ExtPart utility and trying to select the c: I get an error stating: Unable to connect to c: or it does not exist.
Any thoughts?
Thanks,
Was the management console open when you tried it? Try closing it - I believe that when you view the 'Disk Management' snap-in it uses the 'Logical Disk Manager' service which extpart.exe also uses.
If the above doesn't work try running extpart.exe in safe mode. Not ideal, but still far more efficient then attaching a 3rd party .iso or adding the virtual disk to another VM to resize the partition itself.
Booting into Safe Mode solved the issue.
Thanks for the help and this is still easier than the alternatives. Shouldn't there be a way to accomplish this through the VIC?
I guess there *should be* but even the command line utility included with windows (diskpart) doesn't resize the OS volume on the fly. Similarly, most 3rd party partition applications that can be installed onto the operating system will not resize a volume containing the paging file. This is not the case if you boot the VM from a 3rd party app on an .iso or cd/dvd.
If there is no Microsoft utility available to do this effortlessly (i.e. not requiring a separate .iso or cd/dvd and a reboot of the VM) then VMware probably won’t ever (need or want to) modify the UI on the vSphere client.
It worked! No shutdown required.
But beware: when you just run"extpart", the program asks the drive letter. It is essential that you type the letter followed by ":", otherwise the error "Unable to connect to C or it does not exist" occurs.
Hi - on my VM's (v.7 ESX4.0), in the disk provisioning section on the dard disk properties it's all greyed out - can't change the size?
why's that?
Hi Dom, this is probably because
1- you cannot resize virtual disk if there are any snapshot of that VM;
2- you cannot resize IDE disk (IDE disk are used to install windows XP to avoid the SCSI driver installation).
Look at this post on VMware community
http://communities.vmware.com/thread/238733
Thank you. This worked well.
What about to shrink the size of the virtual disk? When i iedit the settings to make it smaller it goes back to the original size. We are importing physical machines to the virtual environment and some disk are way too big....
Hi KK, the easiest way to shrink a VMDK is probably to use VMware converter. This can be done in a few simple steps:
1) Install VMware Converter on the VM that you want to shrink the VMDK(s) of.
2) Run VMware Converter and select the options to 'import a machine' and then 'this local machine'.
3) Select the volumes you want to import and change 'maintain size' to 'type size' and specify your reduced VMDK size(s).
4) Complete the wizard to import the virtual machine
5) Shutdown the original VM and power on the newly imported VM (with the smaller VMDK(s)
Just tried this, worked perfect. Thanks!
I tried this, was not sure it worked as other websites had much more complex ways to do this but this worked amazingly and was so simple!
I just made an extension on volume c:. It runs fine. Thank you
Excellent guide, worked perfectly!
It worked perfect, no shutdown or reboot required and very simple procedure. Excellent! Thank you so much for sharing this! God bless.
I really wished this worked on x64 machines.
This worked a treat, just remember to close the disk manager prior to running the utility.
No its safe mode that's the resolve.
You Must be in safe mode to use the Extpart i think
Thanks Dell
Does anyone have an idea to make this work on a 64-bit OS?
Hi Marcel, I haven't tested this to confirm it but I have read that extpart.exe does work on 64bit machines. It is actually the self extractor that doesn't extract on a 64bit OS. Extract it on a 32bit machine, and try running extpart.exe on your 64bit OS. I would actually be interested to see the result
@James Clements
worked indeed perfectly, thanks! Also found out that you dont need the tool with W2k8. But instead you can use the intergrated disk manager.
Hi Marcel, I should have probably mentioned that as of Windows Server 2008 you can now extend a disk using the Disk Management utility from the computer management console, even if this disk is the Boot/Page File disk.
Thanks for this. I've got my host datastore setup with 406GB and two VM's with 200GB and 150GB however the datastore is only reporting 1GB of free space. If I go and change the VM disk sizes, the change is accepted however when I go back to check the change the old value is there.
Any ideas?
in my vSphere client, when i go into Edit Settings for the vm i want to increase the size of, i am not able to change the size of the disk, all options are grayed out, this is the case when the vm is powered on or powered off. any ideas?
@Jarrod
The only time I have ever seen anything like this was when the datastore that was being presented to the server was larger than the configuration maximum for the version of vSphere that you have installed. So - the vSphere maximum datastore size was 2TB and I presented a 4TB to the host and the host then started to report an incorrect datastore size. I can't think of anything else that may cause this.
@d_frost
There are usually 2 reasons for this happening. The first is that the virtual disk currently has an open snapshot. You will need to commit the changes by deleting the snapshot if you are finished with it. The second reason is that the virtual disk is connected to a virtual IDE controller and not a virtual SCSI controller. Any virtual disks connected to a virtual IDE controller cannot be resized but it is possible to move the disk onto a SCSI controller on the same VM using a method I documented - HERE
Thanks for this solution!
A workmade told me, i should use extpart.exe to extend some c:-partitions on windows server 2003 r2, i tryed and it doesn't work. I found your manual, tested to boot the system in save mode and extend the partition and this solved my problem i've had before with the error "Unable to connect to c: or it does not exist".
Very tks. This articlle solved my issue. I´d like thanks to Mauro Bonder from Brazil.
Thanks Man, Its works for ME !!!
Excellent! it worked for me too.
Awesome! Works like a charm. Does it also work on Dynamic disks?
@Matt
Answered my own question by reading the top of the program.. It doesn't. I purchased Dynamic Disk Converter Server Edition - converted my disk and ran this... Got my terminal server back up and running after it was running out of space on the C drive. Thanks!
@Daniel
Hi Daniel:
Maybe you can try to shutdown the "Windows Search" service ,and try again.
Alex
Stopping the "Windows search" service worked to get rid of the unable to connect message. I am unable to reboot this server without causing major issues, thanks for the tip!!
Rather than using a 3rd party tool like ExtPart, why not just use the WIndows tool DiskPart, it's easy, open a cmd prompt, type 'diskpart' then 'list volume' to display a list of your volumes, then type 'select volume X' (where X is the volume you want to extend), then simply type 'extend', and the volume will be extend to the max size possible, or you can use size=n to increase the volume by 'n' megabytes.
"Unable to connect to c: or it does not exist"
I went through all the non essential services one by one and stopped them and it seems the "File Replication Service" was stopping the connection to the C drive for me.
I needed the vmtools and disk manager turned off. In addition, it was a Citrix server and I needed to turn off the citrix profile service as well.