I just returned from a one week vacation to a warm sunny beach on a small island not too far from Singapore. Even on my vacations my conversations often migrate to technology and my travel mate is an old friend and current employee at VMware, Dave Korsunsky. Sitting by a pool with a cocktail in hand at a fantastic hotel I asked my friend, “what is the right number of hosts per DRS/HA cluster?” Great conversation for a vacation, right?
Maximum Hosts Per Cluster
November 29th, 2010
Nov, 29 2010
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Storage Consolidation (or: How Many VMDKs Per Volume?)
November 7th, 2010
Nov, 07 2010
Part of the performance best practices talk I co-presented at VMworld in San Francisco and Copenhagen focused on answering the question, “How many virtual machines can be placed on a single VMFS volume?” There are a lot of theories as to a best answer. It will not surprise you to learn that no single consolidation ratio works in every environment. Your workloads will influence the maximum consolidation. But we know enough about how ESX virtualizes storage to provide guidance as to the right storage consolidation ratios.
SIOC Event: Ignore or Panic?
November 3rd, 2010
Nov, 03 2010
A colleague of mine recently reported an alarming event witnessed at a customer of both EMC and VMware. After enabling Storage IO Control (SIOC), vCenter reported a possible problem with a datastore. The specific text of the event is:
External I/O workload detected on shared datastore running Storage I/O (SIOC) for congestion management