Thursday, 28 July 2016


(1)How to increase the time limit on snapshot consolidation (2146270) 

Purpose

You can increase the maximum snapshot consolidation time if you want to stun the virtual machine for an extended period of time. 
 
              For example, you may want to increase the consolidation time to resolve an issue when the asynchronous consolidation fails after 10 iterations . By default, the snapshot consolidation time is set to 6 seconds.

Resolution

To increase the time limit of the snapshots consolidation, change the snapshot.maxConsolidateTime configuration parameter in the virtual machine to a higher value, such as 30 seconds:

Note: It is recommended to set this value to an optimum value of 30 seconds as this is usually sufficient to complete the required operations.
  1. Shut down the virtual machine.
  2. Right-click the virtual machine and click Edit Settings
  3. Click the Options tab. 
  4. Under Advanced, click General.
  5. Click Configuration Parameters and add snapshot.maxConsolidateTime = 30.

(2)How to monitor snapshot deletion using esxtop command (2146232) 

Purpose

This article provides information on monitoring the snapshot deletion using esxtop when time stamps are not updating for virtual-mode RDM base disks. 

Resolution

Monitor using esxtop in ESXi 4.x/5.x

  1. Log in as root to the ESX host using SSH. 
  2. Run the esxtop command.

    Note: This command works only if the virtual machine is powered on. 

  3. Press V to see only running virtual machines.

    Note: This is not the same as using the v option.

  4. Find the virtual machine running the consolidation.
  5. Type e to expand.
  6. Enter the Group World ID (value from GID column).
  7. Press Enter.
  8. Make a note of the World ID (ID column) of the snapshot consolidation process:

    • In ESX/ESXi 4.x, the process is called SnapshotVMXCombiner.
    • In ESXi 5.x, the process is called vmx-SnapshotVMX.
  9. Type u to display the disk device statistics.
  10. Type e to expand and enter the device where the snapshot consolidation process is writing to.

    For example: 

    naa.xxx
     value

    Notes:
    • For a regular vmdk file, the device is the datastore that the flat file is located.
    • For a flat vmdk, identifying the datastore device ID can be done by running esxcfg-scsidevs -m.
    • For RDM, the vmkfstools -q against the pointer file reveals the vml ID, which needs to be correlated with the output of ls -l /vmfs/devices/disks/ to get the device ID.
  11. Identify the Group World ID from step 6.

    Note: You may need to sort by MBREAD/s ( press R) or MBWRTN/s (press T) to see the process at the top of the screen.

  12. Look at the number IOPS and throughput for the Consolidation process (WRITES/s and MBWRTN/s columns) to ensure that there is activity and the process is working.

(3)VMware Tools fails with the error: vthread-3, Exception 0xC0000005 access violation has occured.

Symptoms

  • VMware Tools crashes on Windows 2003 terminal server
  • Vmware tools throws pop up error message, you see error message similar to:
vThread-3, exception 0xC0000005 access violation has occurred.

Cause

This issue occurs while accessing a RPCout channel pointer when it is NULL.

Resolution

This is a known issue affecting ESXi 5.1 and ESXi 5.5.

To resolve this issue, upgrade VMware tools.
 

For ESXi 5.1

This issue is resolved in ESXi 5.1 Patch 04, available at VMware Downloads. For more information, see VMware ESXi 5.1, Patch Release ESXi510-201404001 (2070666)

For ESXi 5.5
 
This issue is resolved in ESXi 5.5 Patch 04, available at VMware Downloads. For more information, see VMware ESXi 5.5, Patch Release ESXi550-201501001 (2099265)
 
 
 

(4)OVFtool to Copy VMs from one ESXi host to another.

In today’s post, we will see ow to use OVFtool to copy VMs from one host to another without having shared datastore between them.
The idea behind this article came from one of the questions that were directed to me recently regarding how to copy a VM from one host to another without having shared storage between them.

Now you could perform this from the vCenter Server if both the source and destination hosts are registered to the vCenter Server.
And yes, this operation cannot be performed when the Virtual Machine is in a power ON state even from the vCenter Server.

But if the two hosts were to be standalone hosts, then you could use another VMware product like VMware Converter, but it has its own set of issues.

Another method would be to download the files of the Virtual Machine to your local desktop and upload it to the local datastore of the destination host.

Now you can imagine the complexities and efforts that the above two tasks can take, which is when I came across the ovftool utility and was surprised to see that this can be done with no efforts and is the easiest way to probably do this.

And another good thing about the ovftool is that it is available for Windows, Linux, and MAC Operating Systems.

In our demo here, I will be making use of the Windows msi file to install on a Windows 8.1 machine which has access to both my source and destination hosts.

To download the latest version of the ovftool as of today, use the below link.

Download OVFTool

In our example, I have two ESXi hosts with the IP Addresses 192.168.1.15 and 192.168.1.16. I have a VM called DSL which I am interested in copying from one host to another.

The VM DSL is currently running on host 192.168.1.15 residing on the local datastore of that host (LocalESXiH)
First, you will open a command prompt to navigate to the directory where the ovftool is installed.

Run the below command to connect to the ESXi host remotely.
ovftool.exe vi://root@192.168.1.15
We are making the connection using the root account.
OVFtool to copy VMs
As you can see above, it is listing the VMs registered on the host and Test is one of them.

Now, we just need to specify the source ESXi host and the destination ESXi host as well as the datastore using the -ds option using the ovftool.

The actual copy of the VMs happens through the NFC protocol.
Here is an example of using ovftool to export the VM from one ESXi host to another ESXi host:
ovftool.exe -ds=LocalESXiF vi://root@192.168.1.15/DSL vi://root@192.168.1.16
OVFtool to copy VMs
There we go, you can see that the copy of the VM was successful from the above message.
But a couple of things to remember when you try this.
  • If you have snapshots running on the VM, then it will not copy over the delta files.
  • If you have thin provisioned disk, it will convert to thick provisioned on the destination datastore by default.
If you wish to learn more about the ovftool, kindly use the -h parameter to list out the available options.


 

 
 

 

 

 


 

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