Re-sizing VMDK

pchettri used Ask the Experts™
How safe is to re-size over provisioned VMDK, specially the disk involving Exchange database partition. On my environment vmdk is carved out of netapps ISCSI lun. But my exchange is over provisioned with 1 TB when the database file is only using 300 gb.
I have primary Exchange virtual server hosted on ESX and secondary physical server as DAG /HA member member. I wanted to reduce size of disk to match physical DAG member 830 GB. Would shrinking cause issue with DAG or replication or database?
As Vmware article it sounds safe but I dont know how exchange DB and log on DAG going react to that change.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
This is a quick one, you CANNOT re-size e.g. shrink a Virtual Machine disk easily in VMware vSphere. It's always best to start with small virtual disks and expand, because that's easy, rather than shrink them.

So your options are

See my EE Articles

1. VMware Converter

Part 13: HOW TO: Shrink or Reduce a VMware Virtual Machine Disk (VMDK) using VMware vCenter Converter Standalone v5.5.2

2. Advanced method

HOW TO: Shrink a VMware Virtual Machine Disk (VMDK) in 15 minutes

Both the above methods have a risk, and require downtime.

OR.....the following, is lower risk, more involved simple....

1. Create a new virtual disk, of the correct size. This can be done with the VM powered on.

2. Format and Assign a new driver letter.

3. Use Exchange System Administrator to MOVE the MAILBOXES from current drive to new drive.

4. Remove and delete the old disk.


Shrink volume looks like better option as v2v in my case would be tricky, as I have cluster CNO setup with DAG? I would have to verify with MS about how exchange database replication is able to handle shrink volume from diskmgmt. If I have to drain all services to passive node before shrinking is initiated.
If it could cause issue on database on replication then I may have to leave the over-provisioned disk and may have to re-purpose for low IO backup   or make a repository of ISO files for something.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial