VMware vSphere 5: Say Goodbye to Limited VMDK File Sizes with VMFS-5

In the world of virtualization, VMware vSphere 5 is the latest and greatest iteration of the vSphere suite, offering a plethora of new features and improvements over its predecessors. One such improvement is the upgraded version of the VMware vStorage VMFS volume file system, known as VMFS-5. With this new version, one of the limitations of VMFS-3 has been addressed, allowing for larger VMDK files and more flexibility in planning your datastore infrastructure.

The Problem with VMFS-3

With VMFS-3, the block size you define when formatting the datastore determines the maximum size of the VMDK files stored on it. This means that if you format your datastore with a 1MB block size, you are limited to a maximum VMDK file size of 256GB. While this may not be a problem for smaller environments, it can become a real issue for those with limited storage space.

The Solution: VMFS-5

VMware has addressed this limitation in VMFS-5 by introducing a new unified block size of 1MB, which no longer limits the maximum VMDK file size. In fact, the block size no longer really matters, as the limits are removed completely. This means that you can store larger VMDK files without having to worry about the block size, giving you more flexibility in your datastore infrastructure planning.

Upgrading to VMFS-5

Upgrading from VMFS-3 to VMFS-5 is an online and non-disruptive upgrade operation, which means that you can do it while your VMs are running on the datastore. Additionally, if you have already formatted your datastore with a smaller block size, you can still upgrade to VMFS-5 and extend your VMDK files to the new limits.

Host Upgrade Required

Before upgrading your datastores to VMFS-5, it’s important to update all your hosts to vSphere 5, as vSphere 4 (and earlier) cannot read the new VMFS-5 filesystem. This is a crucial step, as it ensures that your hosts can properly communicate with the upgraded datastores.

Conclusion

The upgraded version of the VMware vStorage VMFS volume file system in VMware vSphere 5, known as VMFS-5, offers a significant improvement over VMFS-3 by removing the limitations on VMDK file sizes. This means that you can store larger VMDK files without having to worry about the block size, giving you more flexibility in your datastore infrastructure planning. With this new version, vAdmins no longer have to worry about the block size as a limiting factor for their VMs. Simplification is always welcome!