martedì 25 giugno 2013

VMware: Merge multiple vmdks into a single vmdk

When importing VMs from Player/Workstation to ESXi sometimes occurr that original vmdk files are separated into multiple vmdks.

This is because vmdks of a fixed small size are sometimes choosen by user creating guest VM in VMware Player/Workstation due to their better transportability respect to a single vmdk of a bigger size.

To merge multiple vmdks into a single vmdk file we need to use Virtual Disk Manager wich comes with VMware Workstation or can be downloaded separately.

If you have VMware Workstation you can find Virtual Disk Manager under:

C:\Program Files\VMware\VMware Workstation

or you can download it as part of vSphere 5.0 Virtual Disk Development Kit.

So, let's merge our vmdks using command promtp and calling for vmware-vdiskmanager.exe.

This is the synthax:

vmware-vdiskmanager.exe -r first.vmdk -t 0 merged.vmdk


-r <sourcediskname>

-t <0|1|2|3>

0 — to create a growable virtual disk contained in a single virtual disk file

1 — to create a growable virtual disk split into 2GB files

2 — to create a preallocated virtual disk contained in a single virtual disk file

3 — to create a preallocated virtual disk split into 2GB files

Here you find more informations about Virtual Disk Manager options while the full manual can be found here.

That's all, happy merging!!

venerdì 14 giugno 2013

VMware: EMC VNX VSA in your lab

Do you have a vLab? Do you need to practice with EMC's Unisphere for managing VNX storage systems? This post is for you!!

In the following article I will explain how to deploy a virtual VNX storage to provide shared NFS storage in your lab. Please note this configuration is just for testing purpouses and not supported for production purpouses.

Let's first have some basics considerations:

VNX Virtual Storage appliance is a virtual machine that runs on a ESXi hypervisor that abstract underlying physical storage, usually local disks, to provide a shared NFS storage platform for all VMs.

Shared storage in a lab is tipically used for testing HA, DRS, Storage DRS, vMotions and Fault Tolerance.

This is a graphical representation of how this VNX VSA will be deployed in your lab:

As you can see physical storage is abstracted by VNX VSA and resulting shared storage is presented as datastore to ESXi hypersor(s) or VMs.

To deploy VNX VSA download it:

Download VNX VSA OVA

Open vSphere Web Client (or vSphere Client if you connect directly to an host or not have deployed vCenter in your lab yet) and deploy your OVA Template.

Power on your VNX VSA and go to console view since we will be prompted to configure networking for a proper startup.

Management IP
Subnet Mask
Default Gateway


Domain name
DNS Server
NTP Server


Create a filesystem and export it as an NFS share on which datastores can be created.

Open your browser and go to Management IP address you setup during initial configuration to access Unisphere management.
Sadly I had to use Internet Explorer to access all functionalities of Unisphere. Neither Firefox, neither Chrome worked in my case.

Login to Unisphere:

Username: nasadmin
Password: nasadmin

Create a new network interface through which NFS share will be accessed so go to Settings -> Network -> Interface Wizard

During interface wizard you will be prompted to select an IP address for this new interface and MTU size (9000bytes if you use Jumbo Frame). Please note that both MTU size and network segment will be accordingly set up in our vSwitches VMKernel ports. But we will go into this later in the article.

Now let's create a filesystem to be shared. Go to Storage -> FileSystem Wizard, and setup filesystem according to your preferences.

And finally create our NFS Export. Go to Storage -> Shared Folders -> NFS -> Create. Choose the filesystem to be shared. the name to which it will be exported and enable hosts to access this share. In my case I inserted the IP of my vLab ESXi host.

Move to our ESXi host(s) networking configuration panel to add a new VMkernel for NFS traffic. As I stated before VMkernel must be in the same network segment of your VNX VSA network interface you previously created.

As you can see in the image above my VMkernel IP is which is in the same 192.168.116.x network segment of VNX VSA network interface When creating VMkernel remember to set MTU according to the previously set one. In my case I set MTU for this VMkernel to 9000bytes.

Final step is to create a new datastore on our NFS export.

This new datastore can be assigned to more than one ESXi hosts.

Here's a slide deck from Simon Seagrave containing some technical informations about EMC VNX and VNX VSA.

That's all!!