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BP1024 Scaling and Best Practices for Virtual Workload Environments with the FS7500 9
• A virtual switch was built on each ESXi host that was used to communicate with the NAS file
systems exported by the FS7500 appliance. A VMkernel (vmknic) port and four uplink NICs
were assigned to the vSwitch as shown in Figure 3.
Figure 3 vSwitch on host
3.2 Test workloads
Iometer workloads were run on 300 GB virtual hard drives assigned to the virtual machines.
Depending on the type of test, up to eight virtual hard drives (vmdk) were assigned to each VM.
The following workloads were run:
• Sequential write with 16 worker threads per drive – representing workloads such as disk
backup, video streaming, and rendering
• Sequential read with 16 worker threads per drive – representing workloads such as DSS/OLAP
database, HPCC, and media streaming
• Random read/write – representing workloads such as OLTP database, e-mail server, web
server, file server, and Virtual Desktop Infrastructure (VDI)
For the random workload, the number of threads per drive was adjusted so that the I/O response time
was capped at 20 ms for reads and writes. Each test ran a single workload type for 30 minutes. Details
on the workload types are shown in Table 1.
Table 1 Workloads
Workload type
Block size
Read/Write ratio
Sequential read
256 K
100% / 0%
Sequential write
64K
0% / 100%
Random read write
8K
67% / 33%
We used these three workload types because they represent common data center I/O patterns over a
variety of enterprise applications.
3.3 NFS network load balancing and redundancy
VMware host storages access with NFS and iSCSI have different mechanisms when using multiple
network paths to achieve network redundancy and increase aggregate network throughput.
iSCSI I/O traffic uses the MPIO stack on VMware and a storage vendor specific plug-in can be
implemented with VMware pluggable storage architecture (PSA) to customize the MPIO functionality
for particular storage architecture. EqualLogic MEM is the EqualLogic specific plugin. One VMkernel
NIC port (vmknic) is associated per iSCSI physical NIC via vSwitch port groups. Vmknic ports are