Dell EqualLogic FS7500 - Manual (Page 6)

Dell EqualLogic FS7500 – Unified block and file storage for virtual workloads
Page 4
Both NAS and SAN infrastructures offer viable alternatives for network storage that may be appropriate
for hosting multiple virtual workloads in VMware environments. So how do you know which
consolidated storage solution is best for you? It depends upon the application, your workload
characteristics, and your datacenter circumstances. The key is to look for flexibility in your storage
solution.
There are two key features that your shared storage solution should provide: scalability and a unified
storage platform. The way a storage solution implements these two features defines whether it will
meet your needs for hosting multiple VMware virtual workloads.
First, a highly scalable storage device can handle a growing virtual implementation simply and easily
without disruptive “forklift upgrades.” That is, expansion should be possible without replacing existing
storage devices with new generation higher-capacity devices and migrating data to the new generation
devices. Multiple generations of storage systems should be able to comingle to provide a single storage
pool with easy expansion or evacuation of capacity as needed. It should also scale performance along
with capacity, so that growth doesn’t lead to performance degradation.
Second, a unified storage system—that is, a system that supports both SAN and NAS storage needs—
simplifies storage and virtualization management. A consolidated management approach to storage
enables IT administrators to easily manage storage needs of all virtual workloads using a single storage
management console. Instead of having to choose between SAN and NAS up front, you are assured that
over time you can remain flexible; choosing the most appropriate networked storage type based on
your application needs.
VMware I/O stacks
VMware virtualized workloads can be hosted on SAN devices using iSCSI, Fibre Channel, or Fibre
Channel over Ethernet (FCoE) block I/O protocol; they can also be hosted on a NAS device using NFS
I/O protocol. The key elements in each of the I/O stacks for these technologies are shown below in
Figure 1.