Wednesday, June 11, 2014

Why I'm moving from blades to traditional rack mount servers for VDI

While blade servers offer numerous advantages in virtualized environments (such as easy scalability, minimal cabling, and ease of setup) as VDI has progressed beyond simple desktop OS virtualization, blades have some significant drawbacks that leaves them less than ideal for hosting a modern virtual desktop if one expects near traditional end user computing performance. 

I'm currently architecting a second generation VDI deployment that currently resides on HP blades.  As the BL685c G6's are approaching five years of age and aren't on the ESXi 5.5 compatibility list, it's time for an update.  With modern developments such as Teradici offload cards, nVidia GRiD accelerated graphics, and affordable PCIe SSDs here is why I'm planning on moving the desktops onto newer standard rack mount 2U hosts.

1.)  Limited Graphics Capabilities
To provide the display performance that a typical user is accustomed to, additional graphics power is necessary.  Most traditional servers include minimal onboard graphics capability and in order to add extra graphics power, you need a PCI-e slot.  While these slots are available in other form factors, such as tower and rack servers, blade options typically don't include a lot in the way of advanced graphics capability, and when they do it adds complexity or expense.

2.)  PCI-Express cards not always available as a mezzanine option
The manufacturer proprietary mezzanine form factor that most blades have for expansion cards limits the expansion capabilities for the blades because it typically takes an extended period of time, sometimes years, for a particular type of card to become available in this form factor (usually either due to the time it takes a server vendor to certify a card or the time it takes a third party vendor to redesign the card into this form factor.)  Also mezzanine cards are sometimes are not backwards compatible with previous mezzanine slots.  For instance HP completely redesigned the mezzanine cards in their G8 generation of servers making them completely incompatible with the mezzanine cards from their older G6 and G7 generations (and vice versa, you cannot use a G8 card in a G6 or G7 slot).  PCI-e is an industry standard and a newer slot can nearly always utilize cards designed to an older specification.

3.)  Local disk storage options for blades are limited and/or expensive
Simply due to a lack of space in their slim form factor.  You aren't going to run VSAN easily on a blade (if at all).  

2 comments: