Right-sizing Your Power and Cooling

We all know that virtualization allows us to do more with less.  Fewer servers and space-saving storage (talk about an oxymoron) help us put some green in the datacenter and back in the budget.  But with tight budgets demanding greater efficiency, virtualization pushing per-U-space utilization higher, and increasingly rack-dense equipment, proper planning of your physical plant remains an essential part of IT.  I argue that right-sizing your power, cooling, and floor-space is more critical now than it has ever been, and is a knowing how to do it is a darn good skill for a virtualization … [Read more...]

Storage Basics – Part III: RAID

This is the third in a multi-part series on storage basics.  I've had some good feedback from folks in the SMB space saying that the first couple posts in this series have been beneficial, so we'll be sticking with some basic concepts for another post or two before we dive into some nitty-gritty details and practical applications of these concepts in a VMware environment.  In the second post of this series I introduced the concept of IOPS and explained how the physical characteristics of a hard disk drive determine the theoretical IOPS capability of a disk.  I then noted that you can aggregate … [Read more...]

ESXTOP Batch Mode Analysis with Windows Perfmon

I needed to grab some stats from my ESX hosts for off-line analysis so I fired up my trusty ESXTOP intent on using batch mode to capture a .csv formatted output.  I started to manually select the counters I was interested in while working in ESXTOP interactive mode (you can save your selected counters to the esxtop configuration file with the 'w' command) and thought that there must be a better way.  I found that better way in the VMware Performance Community: http://communities.vmware.com/docs/DOC-3930.  There is now a -a switch that can be used to include ALL performance counters.  I'm … [Read more...]

Balloon Driver Problems with SQL

I have been meaning to write this up for a while; Scott Drummonds' 'Love Your Balloon Driver' post today at his Virtual Performance blog gave me a nice reminder.  I actually caught a sneak peak at the graphs with an explanation from Scott at his instructor-led lab at VMworld 2009.  Scott calls out that the only workload they discovered suffers from balloon driver activity is Java.  The reason for Java's problems with balloon driver activity is that Java itself runs in a VM and so the guest OS cannot properly determine which pages should be swapped out when the balloon driver calls for … [Read more...]

Obtaining VMware Guest Disk Free Space for NFS Sizing

I am often asked about sizing storage vis-à-vis how much free space within a guest VMDK eats into the overall size of the volume.  The answer can be drastically whether we are dealing with thick-provisioned VMDK's on FC or iSCSI LUN's, or thin provisioned VMDK's on NFS volumes.  The amount of free space present in guest VMDK's also comes into effect when calculating the impact of dedupe on the volume.  Add in some flexible volumes on NetApp storage and the amount of provisioned storage in the design changes significantly. There are several methods of obtaining the amount of free space in a … [Read more...]