We tested midrange NAS devices in our Green Bay, Wis., Real-World Labs with
SourceForge's Iometer 2003.5.10. We used 10 2.4-GHz Pentium 4 client machines,
with network connectivity courtesy of an Extreme Networks Summit7i switch and a
Cisco Catalyst 6500 with a copper Gigabit Ethernet card. Five machines were
hooked to our north subnet and five to our south subnet. On each NAS, one
Gigabit Ethernet NIC was connected to each segment. An 11th machine served
solely as our Iometer console.
Our Iometer tests gauged CIFS (Common Internet File System) performance and NFS
(Network File System) performance.
On the CIFS side, we performed the following tests: 64-Kbps linear read test;
64-Kbps linear write test; 1-MB linear read test; 1-MB linear write test; 2-MB
linear read test; 2-MB linear write test; CIFS IOps and NWC CIFS Generalized
Custom Test.
For all linear read and write tests, the percent read/write distribution was set
to 100 percent read for the read tests and 100 percent write for the write
tests. Percent random/sequential distribution was set at 100 percent sequential.
Our CIFS IOps test had a 512-byte transfer request size, and was also set to 100
percent read and 100 percent sequential.
The NWC CIFS Generalized Custom Test had transfer request sizes of 512 bytes
with 33 percent access distribution, 2 KB with 34 percent access distribution,
and 64 Kbps with 33 percent access distribution. On the 512-byte segment, the
percent read/write distribution was set at 100 percent read and the percent
random/sequential distribution at 100 percent sequential. The 2-KB segment had a
67 percent read and 33 percent write distribution and the percent
random/sequential was set at 100 percent random. On the 64-Kbps segment, we set
the percent read/write distribution to 100 percent read and the percent random/
sequential distribution to 100 percent read.
On the NFS side, we performed these tests: 64-Kbps linear read test; 64-Kbps
linear write test; 1-MB linear read test; 1-MB linear write test; 2-MB linear
read test; 2-MB linear write test; NFS IOps and NWC NFS Generalized Custom Test.
We performed the NFS linear read and write tests with the same parameters as
those of the comparable CIFS tests (100 percent read or 100 percent write, and
100 percent sequential). However, on the NFS IOPS test, we used a 4-KB transfer
request size, rather than the 512-byte size we used for the CIFS test.
Furthermore, our NWC NFS Generalized Custom Test featured transfer request sizes
of 4 KB with 33 percent access distribution, 4 KB with 34 percent access
distribution, and 64 KB with 33 percent access distribution. On the first 4-KB
segment, we set the percent read/write distribution to 100 percent read and the
percent random/ sequential distribution to 100 percent sequential. On the second
4-KB segment, we set the percent read/write distribution to 67 percent read-33
percent write, and the percent random/sequential to 100 percent random. On the
64-KB segment, the percent read/write distribution was 100 percent read and the
percent random/sequential distribution was 100 percent read.