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BP1018 Sizing and Best Practices for Citrix XenDesktop with Dell EqualLogic Storage 30
Figure 15 Read and write IOPS on an individual volume
We did not observe any bottlenecks on the ESXi servers with respect to CPU or memory resources
during the boot operation. The peak CPU utilization observed was around 60% during the boot
process. The system resources on the Citrix Infrastructure ESXi servers hosting provisioning servers
and DDCs were hardly used during the boot storm. The CPU resource utilization on each of the Citrix
Infrastructure ESXi servers while booting VMs was less than 10%.
The network utilization reached a peak of 60 MB during the boot storm and gradually declined once
the master disk image was streamed to all virtual desktops.
This test clearly demonstrated that the storage array was never the bottleneck in our test configuration
and could easily handle the VDI boot storm scenarios.
5.8 Results summary
The key observations from the test results are listed below.
• A single PS6010XVS array was able to host 630 virtual desktops and support the task worker
type of I/O activity. Two arrays were able to host 1270 desktops.
• The VDI I/O represented write-intensive I/O on write cache disks (almost 90% write) and less
read I/O (10% read) on the vDisk. The I/O on vDisk was further reduced because most of the
vDisk data blocks were cached on the PVS RAM.