Horizon View 7 on VSAN – Policies Revisited

It has been some time since I last looked at Horizon View on Virtual SAN. The last time was when we first released VSAN, back in the 5.5 days. This was with Horizon View 5.3.1, which was the first release that inter-operated with Virtual SAN. At the time, there was some funkiness with policies. View could only use the default policy at the time, and the default policy used to show up as “none” in the UI. The other issue is that you could not change the default policy via the UI, only through CLI commands. Thankfully, things have come…

VAAI-NAS, vCloud Director and Cloning Offload Strangeness

I was in a conversation with one of my pals over at Tintri last week (Fintan), and he observed some strange behaviour when provisioning VMs from a catalog in vCloud Director (vCD). When he disabled Fast Provisioning, he expected that provisioning further VMs from the catalog would still be offloaded via the VAAI-NAS plugin. All the ESXi hosts have the VAAI-NAS plugin from Tintri installed. However,  it seems that the provisioning/cloning operation was not being offloaded to the array, and the ESXi hosts resources were being used for the operation instead. Deployments of VMs from the catalogs were taking minutes…

vSphere 5.1 Storage Enhancements – Part 2: SE Sparse Disks

This is possibly the most exciting new storage feature in the vSphere 5.1 release. Space Efficient Sparse Virtual Disks (or SE Sparse Disks for short) were designed to alleviate two issues. Let’s describe these issues first of all. Problem Statement #1 – Let’s take a Guest OS running on a linked clone (View desktop if you will), and this Guest OS issues a 4KB write. vmfsSparse disk (which is the format used by traditional linked clones) has a block allocation unit size of 512 bytes. In other words, this Guest OS is backed by 512 byte blocks. Depending on the…

vSphere 5.1 Storage Enhancements – Part 1: VMFS-5

Welcome to the first in a series of posts related to new storage enhancements in vSphere 5.1. The first of these posts will concentrate on VMFS. There are two major enhancements to VMFS-5 in the vSphere 5.1 release. VMFS File Sharing Limits Increase Prior to vSphere 5.1, the maximum number of ESXi hosts which could share a read-only file on a VMFS filesystem was 8. This was a limiting factor for those products and features which used linked clones. Linked Clones are simply “read/write” snapshots of a “master or parent” desktop image. In particular, it was a limitation for vCloud…