A closer look at EMC ScaleIO

Thanks to our friends at EMC, I was recently given the chance to attend a session on EMC’s new storage acquisition, ScaleIO. This acquisition generated a lot of interest (and perhaps some confusion) as VMware Virtual SAN product seemed to play in that same storage area. My good friend Chad Sakac over at EMC wrote about this some 6 months ago in his evocatively titled blog post VSAN vs. ScaleIO fight! Chad explains where, in his opinion, each product can be positioned and how EMC/VMware customers have a choice of storage options. His article is definitely worth a read.  I…

Storage I/O Control – Workload Injector Behaviour

You may remember an enhancement which we made to Storage I/O Control (SIOC) in the 5.1 vSphere release whereby SIOC can now automatically determine the characteristics and thus the latency threshold of a datastore. Prior to this change, SIOC used either a default value or had customers manually set it. Neither of these were ideal, so we introduced this automatic method. However, there was little detail on how often this latency threshold was calculated. In other words, did the calculation take place when SIOC was first enabled, or is there regular on-going calculations?

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…

A closer look at Dot Hill Systems

Last week, I was at our VMware Partner Exchange event in Las Vegas. Apart from my own break-out session on vSphere 5.1 storage features, I wanted to catch up with a number of our partner vendors who are doing cool things in the storage space. One of these vendors is Dot Hill, a company from Longmont, Colorado, who have been making storage arrays for a considerable amount of time now, but one which does not seem to get a huge amount of exposure. I caught up with Matt Alsip, the Technical Marketing Manager at Dot Hill, to put my customary…

Adaptive Queueing vs. Storage I/O Control

This post is to look at two different technologies available in vSphere to manage the queue depth on your ESXi host(s). A queue determines how many outstanding I/Os can be sent to a disk. In the case of vSphere environments, where many hosts can be doing I/O to the same shared disk device, it can be helpful to throttle the LUN queue depth from time to time when congestion arises. In this post, we will compare and contrast Adaptive Queues with Storage I/O Control (SIOC).

VOMA – Found X actively heartbeating hosts on device

One of the long-awaited features introduced with vSphere 5.1 was VOMA (vSphere On-disk Metadata Analyzer). This is essentially a filesystem checker for both the VMFS metadata and the LVM (Logical Volume Manager). Now, if you have an outage either at the host or storage side, you have a mechanism to verify the integrity of your filesystems once everything comes back up. This gives you peace of mind when wondering if everything is ok after the outage. There is a requirement however to have the VMFS volume quiesced when running the VOMA utility. This post will look at some possible reasons…

vCenter Server 5.1.0b Released

This is a follow-up to my previous post on the 5.0U2. At the same time, VMware also released vCenter 5.1.0b. This post will look at the storage items which were addressed in that update, although the issues that are addressed in the storage space are relatively minor compared to the enhancements made in other areas. Note that this update is for vCenter only – there is no ESXi 5.1 update.