All three of the array-scaling approaches I discussed last week preserve traditional client protocols for connectivity, an admirable goal to be sure. But the inflexibility of these protocols holds the storage industry back, often requiring extreme efforts to achieve simple goals like continuous availability. Attempts to evolve protocols to be more flexible have met with a great … [Read more...] about Scaling Storage At The Client
MPIO
Eight Unresolved Questions About FCoE
Before the holidays, I posed a question on Google+ that generated quite a bit of interest and feedback. Now that it has settled down a bit I'd like to summarize the unresolved elements to make FCoE truly a world-class storage interconnect. Setting the Stage FCoE has been a controversial topic in both storage and networking, and for good reason. No one would deny that Ethernet … [Read more...] about Eight Unresolved Questions About FCoE
VMware PSP and SATP in Plain English
I am often questioned during my Storage for Virtual Environments seminar presentations about VMware's Pluggable Storage Architecture (PSA). This system is fairly straightforward and concept: VMware provides native multipathing support for a variety of storage arrays, and allows third parties to substitute their own plug-ins at various points in the stack. But the profusion of … [Read more...] about VMware PSP and SATP in Plain English
The Four Horsemen of Storage System Performance: I/O As a Chain of Bottlenecks
Why do some data storage solutions perform better than others? What tradeoffs are made for economy and how do they affect the system as a whole? These questions can be puzzling, but there are core truths that are difficult to avoid. Mechanical disk drives can only move a certain amount of data. RAM caching can improve performance, but only until it runs out. I/O channels can be … [Read more...] about The Four Horsemen of Storage System Performance: I/O As a Chain of Bottlenecks
PowerPath To The Virtual People
Hiding in the shadow of the huge VMware vSphere 4 announcement was a very interesting introduction by EMC: PowerPath/VE. As I mentioned in my post on storage changes in vSphere 4, PowerPath/VE plugs into the new pluggable storage architecture (PSA) found in vSphere 4 versions of ESX and takes over the decision-making and heavy-lifting tasks related to communicating with storage … [Read more...] about PowerPath To The Virtual People