With VMware’s announcement of vSphere 6.0, we’ve had a lot of new topics to write about. I’ll be focusing this post on VMware interpretations and implementation of software-defined storage and on the enhancements of VMware Virtual SAN 6.0 in particular. VMware’s strategy is to push for change by driving transformation through the hypervisor until we get to a completely software-defined data center, with all available resources presented and controlled via the hypervisor.
Articles Tagged with SAN
It’s 2015, but you would think it was 1995 based on what we’re still using in our data centers for enterprise storage. We still have gobs and gobs of spinning disks, sucking power and boring us to death while they find our data. Convergence is largely unconverged—we still have separate Fibre Channel and IP data networks, and the only things that got converged were our bills of materials and the sides of our wallets. And for some inexplicable reason, we’re still debating how and when to use flash.
Back in mid-2011, Dell acquired RNA Networks, a small startup out of Portland, Oregon. At the time Dell purchased it, RNA had a product, MVX, that employed three different ways to pool memory across multiple servers in order to accelerate workloads. One was a way to pool memory as a storage cache in order to speed disk accesses using system RAM. In the spring of 2013, we saw some of these features emerge again as Dell’s Fluid Cache for DAS (direct-attach storage) morphed to use the incredible speed of PCIe-based SSDs instead of RAM. Now, in late 2013 at Dell World, we finally get what many of us have been waiting for: the announcement of the expected availability of Dell Fluid Cache for SAN.
This day seemed to start like any other but it seems like as soon as I was logged in to start my day issues arose. It seems like I lost one of my VMware 3.5 ESX servers and all the virtual machines on the host were knocked offline. This should not have been a big deal since HA was enabled but, Murphy’s Law has a way of making life really interesting. So as I logged into the vCenter client I noticed that the host in question was in a disconnected state and all the virtual machines showed up as disconnected. In past experiences I have seen HA, during a host failure, recover the virtual machines in under five minutes. So I waited and waited thinking HA should have kicked in by now. Time for a little further investigation!!
Almost every enterprise that I have spoken to about their experiences in virtualizing anything more than simple or tactical applications has come across one or more that did not perform well once virtualized. In most cases these were applications that used low amounts of CPU and reasonable and predictable amounts of memory, so it stood to reason that resource conflicts in these areas were not the cause of the performance issues. Most of these enterprises had the network support for the virtualized hosts dramatically over-configured with multiple-teamed NIC’s and redundant HBA’s, so there was every reason to believe that the network was most likely not the issue either.