ST1901

TECHNOLOGY FOCUS: VDI FOCUS: VDI
ELIMINATING THE VDI PRICE/PERFORMANCE
BOTTLENECK
DEPLOYING A VDI SOLUTION CAN BE DEMANDING AND EXPENSIVE, WITH STORAGE IN
PARTICULAR A MAJOR POTENTIAL HURDLE, ARGUE JUAN MULFORD AND STEFAN FERRARI OF
ACCELSTOR. INDUSTRY-VALIDATED, COST-EFFECTIVE, ALL-FLASH STORAGE HOWEVER, CAN ENABLE
BUSINESSES ACROSS ALL VERTICALS TO ADOPT VDI
Virtual Desktop Infrastructure (VDI) allows
IT organisations to simplify and automate
the management of thousands of users,
securely delivering desktop-as-a-service from a
central, secure location. Adoption of VDI is
highest in industries where there are both high
levels of regulation and a distributed workforce
or many remote offices (healthcare, banking,
education, retail etc.).
When effectively deployed, VDI delivers high
returns on investment; reducing operating costs
and closing security gaps through infrastructure
consolidation, while also adding flexibility to the
workforce which is now empowered to work
from anywhere.
THE VDI TRAP
Because VDI touches so many users, it directly
affects the productivity and bottom line of the
organisation deploying it. This high level of
visibility puts immense pressure on IT to deliver
performance to ensure a positive user
experience, and this added pressure is the
single biggest roadblock for VDI adoption.
Storage is widely regarded as the biggest
hurdle to overcome from both a cost and
performance perspective.
In order to deliver a user experience on-par
with users having their own desktop, the VDI
infrastructure stack must service bursts of very
high read/write I/O while maintaining ultra-low
latency for all users at once. Failure to do so
leads to the death blow of many VDI projects -
users asking for their desktops back.
According to IDC, most failed VDI
deployments are blamed on storage, as
bursts of high I/O request impact user latency
across the VDI platform. It is unsurprising
then that storage is often the most expensive
and carefully selected hardware in successful
VDI deployments.
Traditional spindle (spinning disk) based and
even hybrid (spindle mixed with flash) storage
have failed to meet the demands of VDI
because these systems depend on a read/write
cache to service low-latency I/O requests -
however once the cache is overwhelmed,
latency increases, the users complain, and the
project dies.
THE ACCELSTOR DIFFERENCE
The storage demands of VDI are so high that
even all-flash storage systems that are
dependent on NVMe or NVRAM caching for
low-latency I/O can fail to deliver a user
experience that leads to a successful VDI
implementation.
With AccelStor there is no cache. Only
metadata is temporarily stored in global
memory, so all write blocks are direct to disk -
meaning all reads come directly from disk.
This cache-less design means all I/O goes
straight to/from the SSD media at near-cache
speeds, significantly increasing performance,
lowering latency, and providing better data
resiliency than traditional cache-based systems.
FLASH-OPTIMISED
RAID was designed in the late 1980s to
provide resiliency and increase performance for
spinning HDD based storage systems. It was
widely successful at the time, so successful in
fact that it is now still the foundation used by
many so-called "state-of-the-art" all-flash
storage systems. These 'RAID optimised for
24 STORAGE
Jan/Feb 2019
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