Cameron Haight

I just came across an interesting paper on a VMware project called PARDA.  The acronym stands for Proportional Allocation of Resources for Distributed Storage Access and represents an attempt to potentially deal with increasing virtualization I/O concerns using a "proportional-share resource scheduler that can provide service differentiation for I/O like VMware already provides for CPU and Memory."  Interesting charts that show that the target is to address latency and not necessarily bandwidth.  While many clients that I speak to suggest that they focus most on memory in terms of costs, they also cite that from a performance standpoint they often concentrate primarily on storage I/O so this could very interesting.  It does though seem to potentially create an interesting scenario for virtualization consumers, i.e.,., do I use a common VM-oriented I/O scheduler that is seemingly independent of the back-end storage, or do I use array-based service controlling mechanisms that may be independent of the underlying VM technology platform?