Heads Up! UNMAP considerations when reclaiming more than 2TB

Thanks to our friends over at EMC (shout out to Itzik), we’ve recently been made aware of a limitation on our UNMAP mechanism in ESXi 5.0 & 5.1. It would appear that if you attempt to reclaim more than 2TB of dead space in a single operation, the UNMAP primitive is not handling this very well. The current thought is that this is because we have a 2TB (- 512 byte) file size limit on VMFS-5. When the space to reclaim is above this size, we cannot create the very large temporary balloon file (part of the UNMAP process), and…

Proximal Data introduces Autocache 1.1 – Guest OS Flash Acceleration

Those of you attending VMUG (VMware User Group) meetings in the US recently may have come across the guys from Proximal Data. They were at the Austin & Silicon Valley VMUGs & I believe they may even have had the key-note at the San Diego VMUG. I had the pleasure of meeting up with Rich Pappas (VP of Sales and Business Development) and storage veteran Rory Bolt (CEO) at VMware’s Partner Exchange this year. They gave me an overview of their new Autocache 1.1 features.

Raxco introduces PerfectStorage – Guest OS Space Reclaim

I was first introduced to Raxco Software when I wrote an article on the vSphere Storage Blog related to fragmentation on Guest OS file systems. In that post, I wanted to highlight some side effects of running a defragment operation on the file system in the Guest OS (actually, primarily the Windows defragger). Raxco reached out to say that they had a product that would actually prevent fragmentation occurring in the first place, which was rather neat I thought. Bob Nolan, Raxco’s CEO reached out to me again recently to let me know about a new product that they were…

Heads Up! Device Queue Depth on QLogic HBAs

Just thought I’d bring to your attention something that has been doing the rounds here at VMware recently, and will be applicable to those of you using QLogic HBAs with ESXi 5.x. The following are the device queue depths you will find when using QLogic HBAs for SAN connectivity: ESXi 4.1 U2 – 32 ESXi 5.0 GA – 64 ESXi 5.0 U1 – 64 ESXi 5.1 GA – 64 The higher depth of 64 has been this way since 24 Aug 2011 (the 5.0 GA release). The issue is that this has not been documented anywhere. For the majority of…

Tintri 2.0 – Per VM Replication Feature

Last week, I had a chance to catch up with Brady Murray and Rex Walters of Tintri. Mostly this was a transfer of information, but the guys let me know that they are on the verge of announcing a new per-VM replication feature which they first demoed to me when I met Tintri at VMworld last year. This will be the main feature in Tintri’s new 2.0 launch.

VMware Mobile Knowledge Portal (VMKP) app version 2.0 is now live!

For those of you who would like to access VMware’s Technical Marketing material whilst on the move, we are pleased to announce version 2.0 of the VMware Mobile Knowledge Portal (VMKP) app is now available. The VMKP contains all Technical Marketing content including Videos, Evaluation Guides, What’s New papers, White Papers & Posters. These pieces of collateral may also be downloaded for offline viewing. This new version now supports Android devices as well as IOS iPad device. Please check out the post by Alan Renouf on the vSphere blog to learn more, see some sample content and the links on…

What are Dependent, Independent Disks & Persistent and Non-persisent Modes?

I had a query about this recently, and actually it is a topic that I have not looked at for some time. Those of you configuring virtual machine disks may have seen references to these different configuration options and may have wondered how they affect the behavior of the virtual machine. Read on to find out the subtleties between Independent Persistent Mode and Independent Non-persistent Mode disks, and what impact they may have.