Many vendors present all-flash arrays (AFA) as the cure-all for virtual desktop infrastructures. Indeed, AFAs can dramatically increase the number of virtual desktops that an infrastructure can support. AFAs also eliminate almost all performance problems; users love their lightning fast desktops. IT professionals need to ask themselves is upgrading to an AFA overkill and are they exposing themselves in other ways?
While an AFA may eliminate VDI related performance problems, it does so at a price. Despite what flash vendors claim, flash storage still comes at a premium compared to hard disks. To justify their claims vendors compare their systems against performance oriented hard disk systems, ignoring capacity optimized HD systems or implementing a small percentage of flash into the architecture. If the IT planner’s only options were either all-flash or all-HD then AFA vendors would be right. But that is not the case.
You Need Flash But do You Need ALL Flash?
The storage infrastructure for VDI environments is not an either or decision. IT planners can also choose a hybrid design, one that leverages flash and hard disk drives (HDD) to deliver the same performance as all-flash, but leverage high capacity HDD to keep costs down. But these systems still require implementing a whole new silo of storage. New flash solutions are available that leverage the existing HDD storage systems within the data center. These systems are an all-flash appliance that automatically move dynamic data to flash internal to the appliance but keeps dormant data on hard disk storage. The cost of performance improvement is a fraction of the cost of an all-flash or even hybrid flash array.
Do You Have to Have Deduplication?
Deduplication can deliver fantastic results, especially in virtual environments and flash vendors count on the technology to appear less expensive than performance HDD systems. But just as flash or HDDs are not the only storage options, deduplication is not the only data efficiency solution. Most VDI environments can use clones that create a golden master desktop that additional desktops leverage. It is important to note that the cloning process is write intensive, so if a hybrid solution is used it needs to support write caching as well as read caching.
While we can make a case against AFAs, there is no denying that they solve most of the storage I/O problems that data centers face, especially in regards to VDI. Naturally, if you can afford and cost justify an AFA, buy it. For organizations that can’t afford it nor cost justify it, then there are other options available that are less expensive and deliver similar results.