We help IT Professionals succeed at work.

no snapshot with VMware ESX 3.5 connected to iSCSI

Medium Priority
Last Modified: 2013-11-14
I've a VMware ESX server (version 3.5.0, 123630) connected with an external iSCSI storage, the Datastore of my virtual machines are on the iSCSI storage.
When i try ti make a snapshot of a VM, apparentely this is done, but when I try to revert or change snapshot image point, in fact, no snapshot is present.
Strange is also that is "very fast" to make the apparent snapshot.

Some one experience the same problem and can help me debug it?

Thank you
Watch Question

As we don't use iSCSI in production due to the potential IO limitations, I've not see this issue and can only make comment of where I would start to look for some answers.
When you initiate a snapshot of the VM via the VC or VI Clienttry to watch the VMFS file system where your guest lives, can you see it build any deltas?
Also look in the VC, Administraton radio button and look at the system logs.
Paul SolovyovskySenior IT Advisor
Top Expert 2008

Is the disk setup as an independent disk?


I've to say that if I keep the default flag on "Snapshot the virtual machine's memory" I got the error message "Failed to take a memory snapshot, since the virtual machine is configured with independent disks".
The snapshot is proceeding only if I remove the flag (but this is a fake, in reality no snapshot is done).

If I browse the Datastore, I can see that the delta file .vmdk is not created!
Usually with a snapshot should be created a delta of the disk named <vmname>-0001.vmdk and a snapshot of the memory in a file named <vmname>-Snapshot1.vmsn

From the VI client I don't see any special error message log.

If I've the VM on the local storage of the server (not on the iSCSI), snapshots are working well fine.

Senior IT Advisor
Top Expert 2008
From VMWare website below. Independent disks are configured so that you can't take a snapshot of it.  Uncheck Independent disk on the hard drive properties and try again

Independent Disks
Independent disks add a layer of control and complexity to your virtual disks. You configure virtual disks in independent mode for certain special purpose configurations.

For example, you may want to run a virtual machine that uses a virtual disk stored on DVD-ROM or CD-ROM. For more information, see Running Virtual Machines from DVD-ROM or CD-ROM Discs.

Or, you may want to exclude one or more virtual disks from a virtual machine's snapshot. For more information about snapshots, see Taking Snapshots.

To configure a disk as an independent disk, choose VM > Settings, select the virtual disk in question, then click Advanced. On the advanced settings screen, select Independent, then the mode for the disk. You have the following options for an independent disk:

Persistent  changes are immediately and permanently written to the disk. All changes to an independent disk in persistent mode remain, even when you revert to the snapshot.
Nonpersistent  changes to the disk are discarded when you power off or revert to the snapshot. Choose this option if you want to run a virtual machine where the virtual disk is stored on a DVD-ROM or CD-ROM, or if you want to lose any changes made to the virtual disk since the snapshot was taken when you revert to the snapshot.

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts


The issue was related to the settings of Indipendent disk.
Changed it, now problem is fixed.
Thank you to all.
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.