add space to C drive VM with adjacent drive

king daddy
king daddy used Ask the Experts™

Anyway I can increase the size of the C drive on a VM that has an adjacent drive? Of course this is exchange 2010 and my M drive (for mailboxes) is adjacent in disk management so adding to space to C drive in VM settings does nothing. Any chance of doing it without powering down? It's windows 2008 R2.

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VMware and Virtualization Consultant
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I think you mean a partition.

This is why, partitions are old legacy, and are best avoided today, and using virtual machines, it's much easier to assign a C: D: E: M: to a single virtual disk, because disk management and expansion is easier.

It's not possible, to expand a C: drive with an adjacent partition on a Basic disk, it can be done with Dynamic disks, but you may not want to use Dynamic disks.

So options are:-

1. Download and Boot using third party partition utilities, first you will need to extend the virtual disk, and then use the Utility, to move the M: partition down the disk, and then expand the C: partition.


2. Add a new virtual disk, copy/move the contents from the M: drive to this new disk. Erase the current M: partition, and then extend the C: drive.

This can be done, ONLINE with Exchange, by using Exchange System Manager to move the Mailboxes/Storage Groups to a new disk. Once the storage group/mailboxes have been moved, you will then be able to extend the C: drive.
Uros Gaberdirector
Depending on your VM host; usually system drives can not be resized live.

If there is truly a need to increase the system drive size I usually go about it this way:
1st. backup current system drive (snapshot or similar)
2nd. shutdown VM
3rd. edit VM settings to increase drive size (this can be done before shutting it down doesn't matter)
4th. boot VM with a "GPartedLive" ISO with which you can then edit the partition table and increase system drive, save any changes and wait for them to propagate
5th. reboot VM

I had done this several times without any issues but the 1st step IS THE MOST IMPORTANT in case anything goes bad and the whole process usually doesn't take more than 30minutes to complete.
Top Expert 2016
Since you tagged it with VMWARE, Andy is totally correct there is no need to have to partitions on a virtual machines hard disk it is not like you have to buy another drive virtual disks are simply files on the host operating system and the # of files is virtually unlimited. Create a new virtual disk, attach the disk, move the files from the 2nd partition and delete it, in disk management change the drive letters so they are correct and then extend the C: drive


thanks guys. I was planning to clean up the exchange databases anyway so moving the contents of M then deleting it will work great to expand C so I am going to do what Andrew said. Since I need space quickly though, I am going to move the transport queue database which is taking up about 17 GBs on C (which may be a whole other issue).

thanks again

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