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
PowerPath
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
Multipath: Active/Passive, Dual Active, and Active/Active
Although it's rare in the PC world, multipath I/O is not new in enterprise IT. I've been juggling paths to storage and networks as long as I've been a systems administrator, and that's a bit longer than I care to admit. But the proliferation of technologies has made it difficult to understand path management. What's the difference between "dual active" and "active/active"? Is … [Read more...] about Multipath: Active/Passive, Dual Active, and Active/Active
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
Storage Changes in the VMware vSphere 4 Family
VMware officially launched their next-generation (version 4) enterprise family of products today under the "vSphere 4" name. As I've been doing for the last few major ESX releases, I'm focusing this post on the storage changes present in vSphere 4. For more information on earlier updates, see my articles: Storage Fixes in VMware ESX Server 3.5 Update 2 Storage … [Read more...] about Storage Changes in the VMware vSphere 4 Family