Issue link: https://epubs.iltanet.org/i/98946
www.iltanet.org IOPS by disk type: • 15k SAS = 175 to 180 IOPS • 10k SAS = 125 to 130 IOPS • 7.2k SATA = 80 to 90 IOPS • SSD Drive = approximately 8,500 IOPS Optimizing Performance Once you lock down the proper disk design, another important consideration is when to use Machine Creation Services (MCS) and when to deploy Provisioning Servers. Remember that the goal is to deliver a streamed, nonpersistent desktop to your user community. Simply standing up static VDI desktops offers some value, but leaves behind the need to individually update and manage virtual machines — not the ideal outcome when making this level of investment. As a general rule of thumb, when deploying in firms with more than 100 VDI desktops, redundant physical Provisioning Servers, isolated on a dedicated VLAN are typically recommended for optimal performance. Remember, this network is to be used for serving images, not cache. In environments with less than 100 VDI desktops, Machine Creations Services can typically handle the job. And finally, be sure to measure thrice when designing your VDI system. A Few "Gotchas" So you're ready to upgrade to Windows 7 and Office 2010 and want to make the leap using VDI. Beware of one of the most common pitfalls: poor system performance due to processor power management enabled in the host server's system BIOS. Power management utilities are common on modern hardware and go by names such as Intel SpeedStep and AMD PowerNow! After disabling BIOS-based CPU power management tools, CPU speed can increase up to 60 percent! This is probably the most common performance factor discovered during VDI system assessments. Another "gotcha" that IT managers ponder is what to do with nonpersistent data; data that must be recreated at system login/machine creation and can cripple the VDI desktop experience. Usual suspects include Windows Index and Outlook OST files. FOLLOW THESE STEPS TO ENSURE PROPER VDI DESIGN, SPECIFIC TO YOUR PARTICULAR ENVIRONMENT. 1. Perform detailed design and planning, and know your applications. Measure boot and login on a physical PC first (boot time, login time and disk IO). 2. Perform load infrastructure testing using a tool such as Login VSI. 3. Perform traditional user experience testing and pilot testing to obtain a passing grade prior to firmwide deployment. 26 ILTA White Paper