24
Figure 5:
VDI IOPS
Other deployment and operational items, such as patching and environment refreshes,
can also create tremendous spikes in IOPS and will affect performance if not accounted
for and planned accordingly. If one deploys another 50 virtual desktops, that action can
create a significant I/O spike. For these reasons, the storage architecture must be
designed to accommodate peak IOPS from maintenance operations.
There are a number of ways to architect VDI solutions with full clones or shared image
presentation and each can have different effects on storage requirements in terms of
both capacity and performance. Since full clones consume additional capacity and
storage, deduplication will be important. Full clones must also be patched independently,
which will increase the I/O during those operations.
The shared image approach that Citrix offers with MCS or PVS, and VMware with linked
clones, presents different I/O challenges. By nature, these shared image approaches
require less storage capacity since the parent image is shared and each virtual desktop
is only consuming a smaller amount of space for its unique data. The shared image has
different performance requirements than the typical VM. This image is now used by
hundreds or thousands of virtual desktops and must be able to generate large amounts
of IOPS. If the shared image is a bottleneck, all virtual desktops using it will be negatively
affected and user experience will be bad.
MS Word
MS Excel
Acrobat
MS Update
1000
IOPS
800
IOPS
1400
IOPS
2500
IOPS
15
IOPS
15
IOPS
15
IOPS
15
IOPS
15
IOPS
