New Article: VMware CPU Hot Plug vNUMA Effects on SQL Server

My latest article on SQLPerformance.com was published today and highlights the potential for performance problems while using the hot-add vCPU feature in ESX 5+ with wide VMs for SQL Server. http://www.sqlperformance.com/2013/12/system-configuration/vmware-cpu-hot-plug-vnuma-effects-on-sql-server This is a potentially hidden problem with serious performance implications that should be checked for if you are using VMware to run wide VMs […]

Hyper-V Equivalent to VMware CPU Ready Time

I’ve blogged about CPU Ready Time in VMware in the past, and one of the questions I am often asked is whether there is an equivalent counter in Hyper-V? The definition of CPU Ready time by VMware is: “Percentage of time that the virtual machine was ready, but could not get scheduled to run on […]

The Accidental DBA (Day 24 of 30): Virtualization High Availability

This month the SQLskills team is presenting a series of blog posts aimed at helping Accidental/Junior DBAs ‘keep the SQL Server lights on’. It’s a little taster to let you know what we cover in our Immersion Event for The Accidental/Junior DBA, which we present several times each year. If you know someone who would benefit from […]

The Accidental DBA (Day 12 of 30): Backups: VM Snapshots

This month the SQLskills team is presenting a series of blog posts aimed at helping Accidental/Junior DBAs ‘keep the SQL Server lights on’. It’s a little taster to let you know what we cover in our Immersion Event for The Accidental/Junior DBA, which we present several times each year. If you know someone who would benefit from […]

Querying the VMware vCenter Database (VCDB) for Performance and Configuration Information

In my previous post I showed how DBAs can be provided with read-only access to Virtual Center for monitoring VM performance in the data-center   One thing that many administrators don’t realize or think about is that Virtual Center uses a database for storing information about the virtual data center and the most common database platform used […]

Read-Only Access to Virtual Center for DBAs

Most environments using VMware for server virtualization are going to also have Virtual Center Server installed for administration and monitoring.  As a DBA, I always had access to Virtual Center with limited permissions.  It is incredibly easy for VM administrators to provide read-only access to Virtual Center to non-administrators so that they can monitor the […]

CPU Ready Time in VMware and How to Interpret its Real Meaning

(If you’re having persistent problems with your virtual machine configurations and SQL Server performance, Jonathan can help you fix it – fast! Click here for details.) In the last month I have had to explain how to interpret CPU Ready Time information for SQL Server VMs running on VMware to a number of people. The […]

Clustering SQL Server on Virtual Machines (Round 2)

Recently there was lengthy discussion on the #sqlhelp hash tag on Twitter about clustering SQL Server on VMs and whether or not that was a good idea or not. Two years ago I first blogged about this same topic on my blog post, Some Thoughts on Clustering SQL Server Virtual Machines. If you haven’t read […]

Fixing VirtualBox “Could not find an open hard disk with UUID” Errors with Differencing Disks

A few weeks back, I needed to make space on my laptop SSDs for some new VMs for future training classes we’ll be doing and as a part of doing this I decided to copy a number of my VirtualBox VMs to an external hard disk.  What I had expected was that this would work […]

How much memory does my SQL Server actually need?

Traditionally questions about how much memory SQL Server needs were aimed at how to appropriately set the 'max server memory' sp_configure option in SQL Server, and in my book the recommendation that I make is to reserve 1 GB of RAM for the OS, 1 GB for each 4 GB of RAM installed from 4–16 […]

SQL Server and VMware: A Potentially Fatal Combination? That’s Nonsense!

This morning Paul received an email from a member of the community that was asking if it is safe to run SQL Server inside of a VM and whether we would suggest running databases in virtual machines or not.  The root of the question being asked was an article that the person had read back […]

Some Thoughts on Clustering SQL Server Virtual Machines

On my blog post Virtualizing SQL on VMware Reference List, Oscar Zamora (Blog | Twitter) asked the following question in a comment: As a virtualized instance has the benefit of "failing over" to another physical box, would you consider clustering a virtualized instance? The answer to this question more than I want to write up […]

Virtualizing SQL on VMware Reference List

I’ve been managing SQL Server virtualized in production environments for nearly five years now, and in that time, I’ve had to do a significant amount of reading/learning about VMware as a hypervisor so that I could properly track down performance problems and in a lot of cases, prove to vendors that the problem wasn’t virtualization.  […]