I have a virtual server that is constantly running, lately we tried to do a backup for it and we were surprised that the modification date of all the image files is a couple weeks old. We are trying to take a backup of the server VM image every 6 hours while keeping the server running but since the files are not being modified we are not sure how to force VM to update the server files so we can back them up.

Any ideas?

EDIT: Just wanted to add that the VM in question is an Ubuntu Server VMWare Workstation image.

EDIT2: A screenshot of the directory that contains the VM files is shown below. Note that we restarted the host machine on September 9th and since then the files did not change although the VM has been up and running for two days now.

enter image description here

  • VMWare workstation would not be my choice to run a server on. Are there snapshots on the guest or were there snapshots taken at any time on the guest? – Rex Sep 11 '14 at 8:04
  • No snapshots were taken on the guest. – Zaid Amir Sep 11 '14 at 8:05
  • Can you add a screenshot of the directory in question with all the files for that virtual machine? – Rex Sep 11 '14 at 8:13
  • @Rex I have added a screenshot of the folder. – Zaid Amir Sep 11 '14 at 8:31

It's normal for date / time stamps not to change when a file is locked exclusively and/or there's high disk activity on that file. NTFS delays updating those entries or may not do them at all, until the VM is completely shut down by VMware Workstation. Are you using a specialized backup tool? If yes, this shouldn't be an issue. And, Rex is correct, too, snapshots or differencing disks are another natural way to get VMDKs to remain static as all write operations are gated to the differencing VMDK

  • So is there a way to schedule snapshots creation in Workstation? Or must I do it manually on regular intervals. I don't see any options in VMWarwe Workstation to schedule snapshot creation. – Zaid Amir Sep 14 '14 at 5:29

I can't comment yet due to my newbie score ;-)

In order to schedule VMware snapshots, use the Windows Task Scheduler, configure a new task to use your personal logon and use the tool provided called vmrum: C:\Program Files (x86)\VMware\VMware Workstation

syntax: vmrun -T ws snapshot "c:\my VMs\myVM.vmx" mySnapshot

As with all snapshots, they aren't really a backup copy and are prone to all kinds of errors and corruption. At the very least they affect performance, so I usually don't use them at all

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