Database Reference
In-Depth Information
VMware has designed vSphere's storage multipathing to be flexible and to allow
storage vendors to write their own multipathing plugins. The advantage of many of the
third-party vSphere multipathing plugins, such as EMC's PowerPath/VE, is that they use
target-side load balancing. This is where the load on the storage array's paths, storage
processors, and individual queue depths may be taken into consideration when choosing
the best path for a particular IO operation. This can produce greatly improved
performance and lower latency. Many vendors offer their own plugins, so you should
check with your storage vendor to see if they have a plugin and what advantages it might
have for your environment. Most of these plugins come at an additional cost, but in our
experience it can usually be justified based on the additional performance.
Tip
When using iSCSI-based storage and the Software iSCSI initiator, ensure that you
configure the iSCSI Port Binding in vSphere correctly so that you can get the best
performance and reliability from your storage. Refer to the “VMware Multipath
Configuration for Software iSCSI Using Port Binding” white paper
configuration-software-iSCSI-port-binding.pdf
).
The VMware vSphere Native Multipathing modules eliminate a lot of the problems and
complications traditionally associated with in-guest multipathing drivers. To simplify
your environment further, you could choose to put your VMDKs onto NFS data stores
mounted to vSphere. When using NFS, your load balancing will most likely be done on
the array, or by using the correct network teaming. NFS as a data store instead of VMFS
is a great solution, provided it is designed and deployed correctly to meet the
performance needs of your SQL Servers. The protocol itself will not be your limiting
factor for performance, especially on 10GB Ethernet. Whichever storage option or
protocol you choose, you just need to design it to meet your performance requirements
and verify through testing that it does. There are many situations where NFS could be a
Hyperconverged Infrastructure
.”
vSphere 5.5 Failover Clustering Enhancements
In response to customer demands for increasing levels of database availability over and
above the 99.9% easily obtainable with vSphere HA, VMware has provided a number
of enhancements to the support of Windows Failover Clustering over the years. From
vSphere 5.1, VMware supported five-node Windows Failover Clusters, where it
previously supported only two nodes. In vSphere 5.5, VMware has again enhanced the
Windows Failover Clustering support, and this is particularly relevant to high-
