I had a question on my old VMFS LUN Sizing article I did back in 2009… The question was how valid the used formula and values still were in today’s environment especially considering VMFS-5 is around the corner. It is a very valid question so I decided to take my previous article and rewrite it. Now one thing to keep [...]

I was just playing around with vSphere 5.0 and noticed something cool which I hadn’t noticed before. I logged in to the ESXi Shell and typed a command I used a lot in the past, vmkfstools, and I noticed an option called -K. (Just been informed that 4.1 has it as well, I never noticed it though… ) -K –punchzero [...]

A lot has changed with vSphere 5.0 and so has one of the most under-appreciated “features”…. VMFS. VMFS has been substantially changed and I wanted to list some of the major changes and express my appreciation for the great work the VMFS team has done! VMFS-5 uses GPT instead of MBR VMFS-5 supports volumes up to 64TB This includes Pass-through [...]

Last week I noticed that one of the articles that I wrote in 2008 is still very popular. This article explains the various possible combinations of the advanced settings “EnableResignature” and “DisallowSnapshotLUN”. For those who don’t know what these options do in a VI3 environment; they allow you to access a volume which is marked as “unresolved” due to the [...]

We had a discussion internally about ESX/ESXi caching I/Os. In particular this discussion was around caching of writes  as a customer was concerned about consistency of their data. I fully understand that they are concerned and I know in the past some vendors were doing write caching however VMware does not do this for obvious reasons. Although performance is important [...]

I was just answering some questions on the VMTN forum when someone asked the following question: Should I upgrade our VMFS luns from 3.21 (some in 3.31) to 3.46 ? What benefits will we get? This person was referred to an article by Frank Brix Pedersen who states the following: Ever since ESX3.0 we have used the VMFS3 filesystem and [...]

I was reading about Storage Filters last week and wanted to do a short write up. I totally forgot about it until I noticed this new KB article. The KB article only discusses the LUN filters though and not the other filters that are available today. Currently 4 filters have been made public: config.vpxd.filter.hostRescanFilter config.vpxd.filter.vmfsFilter config.vpxd.filter.rdmFilter config.vpxd.filter.SameHostAndTransportsFilter The first filter [...]