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There are a number of different storage resource requirements that exist with any EUC
design. It will need to account for server-based VMs, user data, and virtual desktop
infrastructure (VDI). The VDI storage requirements will be the most demanding within
the environment and are also the ones that cause most VDI projects to fail or suffer
from a bad experience.
For this reason, the storage portion of this eBook focuses on the needs of the VDI
service of the solution. The needs of each virtual desktop can often seem small and
insignificant, but when you combine them into large groups as the storage scales,
performance demands can easily overwhelm storage that was not properly designed
to meet these needs.
If each virtual desktop averages 15 IOPS and one expects 2,000 concurrent users, that
amounts to 30,000 IOPS. That number is pretty large and could overwhelm the average
storage array. But one cannot simply design the storage solution to meet the average
I/O of the environment, the design must account for peaks, including desktop boots
and user login events.
Virtual desktop workloads have very spiky I/O, which makes them very different from
other types of workloads within the average enterprise datacenter. For example, opening
an application like Outlook for the first time in a session can generate upwards of 1,000
IOPS for that one user session. That is far beyond the average 15 IOPS discussed earlier.
An example of different application IOP impact is shown in Figure 5.
Storage Requirements
