The Solutions Lab team conducted single server scalability tests for various FlexCast models, in which we determined the server capacity through the achievement of VSImax for hosted virtual desktops on a single Cisco UCS B200 M3 blade.  This is the first in a series of blogs examining the results.

The following hardware and software components were used to perform the tests:

The virtual desktops used in our tests:

  • hosted virtual desktop (Provisioning Services streamed with write cache on SSD)
  • hosted virtual desktop with Antivirus (Provisioning Services streamed with write cache on SSD)
  • hosted virtual desktop with Personal vDisk (Provisioning Services streamed with write cache on shared storage)
  • hosted virtual desktop with Personal vDisk and Antivirus (Provisioning Services streamed with write cache on shared storage)

This blog focuses on hosted virtual desktop tests. For testing, CPU utilization reached 100%, which was the bottleneck that triggers the VSImax.

Test Methodology

For the tests, all sessions were launched within 30 minutes.  The Login VSI medium workload with Flash was used  to determine the appropriate scalability numbers using VSImax Dynamic response time.  This workload represents office productivity tasks for a “normal” knowledge worker and includes operations with Microsoft Office, Internet Explorer with Flash, printing, and PDF viewing.

Multiple test runs were executed, each run returning the same VSIMax number, +/- 1%.  The findings below show the results for one test run for each test performed.

Findings

Single Server Scalability Tests for Provisioning Services streamed hosted virtual desktops with write cache on SSD

To find Login VSImax for hosted virtual desktops with write cache disk on the local storage repository (SSD) on a single blade, we used a test workload of 215 users running Windows 7 SP1 sessions under a medium workload (including Adobe Flash content).  As Figure 1 shows, Login VSIMax was reached at 202 users.

To find Login VSImax for hosted virtual desktops with McAfee MOVE and with write cache disk on the local storage repository (SSD) on a single blade, we used a test workload of 195 users running Windows 7 SP1 sessions under a medium workload (including Adobe Flash content).  As Figure 2 shows, Login VSIMax was reached at 157 users.

Parameter hosted virtual desktops hosted virtual desktops  with AV
Virtual CPUs 1 vCPU 1 vCPU
Memory 1.5 GB 1.5 GB
vDisk size 40 GB 40 GB
Write Cache size 4 GB 4 GB
PvDisk size 10 GB 10 GB
Virtual NICs 1 virtual NIC 1 virtual NIC
vDisk OS Microsoft Windows 7 Enterprise (x86) Microsoft Windows 7 Enterprise (x86)
Additional software Microsoft Office 2010, Login VSI 3.7 Microsoft Office 2010, Login VSI 3.7, McAfee Move
Test workload Login VSI “medium” workload Login VSI “medium” workload
Test Size 215 195
VSI Max 202 (Figure 1) 157 (Figure 2)
Figure 1: hosted virtual desktops (SSD), Single Server Results
Figure 2: hosted virtual desktops (AV, SSD), Single Server Results

Following are the CPU, memory, and network metrics collected for the corresponding VSI max data.

Figure 3: hosted virtual desktops (CPU)
Figure 4: hosted virtual desktops with AV (CPU)
Figure 5: hosted virtual desktops (Memory)
Figure 6: hosted virtual desktops with AV (Memory)
Figure 7: hosted virtual desktops (Network)
Figure 8: hosted virtual desktops with AV (Network)

Conclusions

Login VSImax for hosted virtual desktops with write cache disk on the local storage repository (SSD) on a B200M3 blade was reached at 202 users with a medium workload (including Adobe Flash content).

Login VSImax for hosted virtual desktops with McAfee MOVE and with write cache disk on the local Storage repository (SSD) on a B200M3 blade was reached at 157 users with a medium workload (including Adobe Flash content), which represents a drop of approximately 22% compared with the  hosted virtual desktops without antivirus solution.

These numbers represent the maximum capacity of B200M3 which occurs when CPU utilization reaches 100% with XenServer 6.1 for the described above types of virtual desktops. The CPU utilization was used to determine maximum recommended load for a single blade that should not exceed 95%.

Upcoming blogs will look at hosted virtual desktops with Personal vDisk (Provisioning Services streamed with write cache on shared storage) with and without Antivirus.

(To be continued)