VMworld is just a few months away. And this year I submitted along with Eric Sloof (@esloof) a session called Snapshot Deepdive.
Snapshot deepdive
Making a snapshot of a virtual machine is one of the most common tasks an administrator can do with a virtual machine. Snapshots make our life must easier by providing a robust roll-back scenario when performing a upgrade or when we change the configuration of a virtual machine. Snapshots are quest independent and easy to use.
Snapshots can also be a real nightmare when used wrong.
Datastores can fill up resulting in a virtual machine (suspension) crash., you’re unable to delete snapshots and backup programs leaving unmanageable snapshots behind. These are all common issues that can occur when using snapshots. What about the size of a snapshot file, how large can a snapshot file grow?
This session will give you a deepdive in how snapshot actually work in the different version of vSphere and how you can solve common problems when working with snapshots.
As of today public voting is open. If you like the session proposal of Eric and myself please vote!
The public voting ends June 8.
Last weekend I implemented a new storage DRS cluster for a customer of mine. I must say, storage DRS rocks! But this is off topic for this post. If you want to know more in depth storage DRS stuff. Check Frank Denneman website.
After I implemented the storage DRS cluster I wanted to move about 60 virtual machines onto the new datastore cluster. These virtual machines where all Windows 7 virtual machines because the customer runs VMware View. So I selected the blue folder where the virtual machines resides and sorted the view on power state. First I selected the power off virtual machines and initiated a migration to the new datastore cluster. Second I selected the powered on virtual machines and also initiated a migration to the new datastore cluster. Then it was off to bed.
The next morning I check the result finding that about 20% of the virtual machines where not moved and that about 5% of the virtual machines where move according to vCenter but when I checked the datastore browser I still saw the original virtual machine home directory.
After some investigation where problem was 2 sided.
Storage vMotion doesn’t migrate all of the files that are in the virtual machine home directory.
Only files that native belong to a virtual machine are migrated to the destination. In my case the customer experimented with creating a screenshot of a virtual machine. This option makes a .png file in the virtual machine home directory. A storage vMotion doesn’t migrate the kind of file, so in the final phase of a storage vMotion the virtual machine files are deleted on the original datastore but not the ‘non-native’ file, making the deletion of the original virtual machine home directory impossible.
Because off performance reasons I can imaging that VMware only migrate ‘native’ virtual machines file. Imaging that somebody accidentally places a 8 GB DVD ISO file in the virtual machine home directory. That file is also migrated. On the other hand, maybe I wanted these kind of files in the virtual machine home directory. And know these file aren’t migrated. And how many of the VMware administrators check if the original home directory is really deleted on the original datastore? Not many I guess.
I think it would be nice it VMware changes this in the next update or release.
Power state changed while waiting for a storage migration
The virtual machines where Windows 7 virtual machines because the customer runs VMware View. The maximum total concurrent storage vMotion is 6. As I wanted to move 50 virtual machines 44 had to wait. During this wait period, the View broker powered down several virtual machines because the user logged out.
I noticed this behavior before when I use scheduled tasks in vCenter. I’m not sure why vSphere doesn’t check the power state of a virtual machine again when it started migration. For me it doesn’t matter if the machine is powered on or powered off. I just wanted it to be migrated to the destination. This makes storage vMotion a bit less usable for migrations of many virtual machines at the same time that change power state now and than.
Never the less I find storage vMotion a great tool! But in combination with VMware View……..?
Just a quick post. Last week I received a mail from VMware with information about the vExpert 2012 program. One of those items was a link to the new vExpert 2012 logo. So I thought to share this with you guy’s.
I was upgrading some VMs that were a member of a vApp.
During the process I noticed that all the VMs had really old snaphosts. As most of you probably know leaving a VM in snapshot mode for a long time isn’t wise because it can fill-up your datastore. So I removed the snaphosts from the VMs. 1 VM deleted its snaphost quickly, so I powered the VM on. During the power on stage I got the error:
The operation is not allowed in the current state
It didn’t took me long the discover the problem. The other VM was still deleting his snapshots, preventing the other VM powering up.
Though I find the behavior strange. You cannot snapshot a vApp at once and why doesn’t VMware allow me to power on a VM in a vApp when another VM is deleting his snaphosts?
VMware | Michael May 30, 2012 | 
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