Tag Archive for vdi

VMware View 5.1 Storage Accelerator

With the release of VMware View 5.1 a number of new features have been introduced, particularly around storage performance. For me, the key feature is the View Storage Accelerator, or you may hear it referred to as Host Caching.

Without going into intricate detail, the storage accelerator basically creates an additional file within the datastores for the replica disk and all linked clone OS disk. This file is know as a digest file and is used as a caching mechanism. The way this digest file increases performance is by minimising the amount of read requests back to the replica disk. This is done by caching commonly read blocks from the replica disk into the OS disk digest file which can be read directly acting as a cache. This can help minimise boot and log on storms within your View environment.

Enabling the Storage Accelerator is relatively simple and can be achieved by following the below steps.

Step 1. Log in to you VMware View administrator console, under View Configuration click servers. Locate your vCenter server and click Edit.

Step 2. Click on the Host Caching tab then check the Enable host caching for view check box. This will enable the caching capability and allow you to specify the size of the cache for all, or individual hosts. The minimum cache size is 100MB with a maximum of 2GB. Click OK to apply the change.

Step 3. Locate a linked clone pool you want to enable the storage accelerator on and Edit the settings. Click on the far right tab named Advanced Storage and check the Use host caching check box. Click OK to apply the settings.

The storage accelerator features is now enabled for this linked clone pool, and will require a recompose to generate the necessary digest files. Hopefully you will now see a performance increase on read intensive operations.

Thanks for reading.

How To Record Storage IOPS

In this post we will run through how to record or capture the amount of IOPS being generated by one of your systems. The method we will be using is the Windows Performance Monitor (perfmon). I used this method for recording the IOPS from desktops computers at my workplace when sizing for a VDI project, so lets get started.

Step 1. Click right on Computer and select Management. Under Performance > Data Collector Sets > User Defined. Click right on the User Defined folder and select New Data Collector Set.

Step 2. Set a name for your performance counter and select Create Manual Advanced and click next.

Step 3. Click Create Data Log and check Performance Counter then click next.

Step 4. Set the time interval to 10 seconds and click Add.

Step 5. Locate Local Disk from the left hand menu and add the options (Disk Reads/sec, Disk Writes/sec, Disk Transfers/sec) and click OK.

Step 6. Double click on the item made under the User Defined folder and right click on the Data Collector and select Properties.

Step 7. Under log format, select Comma Separated and click OK.

Step 8. Select the performance counter and click the play button to start collecting data.

Step 9. Once you have collected  your data for a period of time, navigate to the following location C:\PerfLogs\Admin\yourcountername. Now load the Excel document to display your collected IOPS. Within the excel document you can calculate figures such as the average IOPS, maximum IOPS, as well as putting together a graph that illustrates the activity of the IOPS by specifying the Read and Write columns.

Thanks for reading and lookout for my other articles on storage and IOPS calculations.


VMware View Scheduled Recompose

In this post we’ll go over writing a View PowerCLI script to schedule a recompose of a desktop pool.

If your like most VMware View administrators you’ll probably use linked clones, and know that now and again these clones will need recomposing to keep up to date with operating system patches or updates for embedded applications. If your organisation is like mine and operates on a 24 hours basis, getting downtime to perform a recompose can end up being headache and is usually scheduled for a unsavory hour.

Unfortunately scheduled tasks was not part of the View v5 release which i imagine left many people in my situation slightly disappointed. To get around this need for functionality, i turned to the View PowerCLI extensions and wrote a script to perform my desired tasks.

Below you will fine my script, along with one of my working examples that allows you to specify a linked clone pool to be recomposed from a specific virtual machine and snapshot at a defined time and date.


Script: Get-Pool -pool_id your-pool-id | Get-DesktopVM | Send-LinkedCloneRecompose -schedule ‘yyyy-MM-dd-23 hh:mm’ -parentVMPath “your-parent-vm-path” -parentSnapshotPath “your-snapshot-path


Example: Get-Pool -pool_id LC-EXT-H2F | Get-DesktopVM | Send-LinkedCloneRecompose -schedule ’2012-01-23 11:42′ -parentVMPath “/Hangar 1/vm/VMware View/Linked Clones/viewpocmlc” -parentSnapshotPath “/Base Windows 7 Image/Base Windows 7 Tweaked/Windows 7 with Basic Apps”


Below is an example desktop pool’s options which details the paths for -parentVMPath shown under Parent VM, and -parentSnapshotPath shown under Image.

Thanks for reading and be sure checkout how to schedule the refresh of a desktop pool Here