Heads Up! VOMA – ERROR: Trying to do IO beyond device Size

This is a short note on trying to use VOMA, the vSphere On-disk Metadata Analyzer, on a dump taken from a VMFS-5 volume which was upgraded from VMFS-3. This is not an issue if VOMA is run directly on the volume; it is only an issue if a dump is taken from the volume and then you try to run VOMA on the dump. It may error during phase 1- ‘Checking VMFS header and resource files‘ with an error ‘ERROR: Trying to do IO beyond device Size‘. When a VMFS-3 is upgraded to VMFS-5, a new system file, pb2.sf, is…

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…