5. Write Performance

As I do with all NAS testing, I used IOzone to check out the file system performance on the NV (the full testing setup and methodology are described on this page).

I tested with each model and computer running iozone connected via a 10/100 switch, then moved them to a NETGEAR GS108 10/100/1000Mbps switch for gigabit-speed testing. I used the GS108 engineering sample [reviewed here] that supports jumbo frames up to 9k.

The iozone computer connected via an Intel PRO/1000 MT Desktop gigabit Ethernet adapter, which was set to auto-negotiate its connection speed.

NOTES:

Firmware version tested was v2.00c1-p8 [1.00a014] Unless otherwise noted, default settings included disk write caching enabled, journaling enabled, full journaling disabled, CIFS fast writes enabled All testing was done in RAID 5 mode Drives used were four Seagate Barracuda ST3250823AS 250 GB 7200RPM SATA hard drives with 8 MB of cache Keep in mind that the maximum raw data rate for 100Mbps Ethernet is 12500 kBytes/sec and 125000 kBytes/sec for gigabit

Figure 7 shows a 3D surface plot of the NV's write performance using file sizes from 64 kBytes to 128 MBytes and record sizes from 4 kBytes to 16 MBytes with a 100Mbps connection. Note that the plot is oriented so that larger file sizes are closer to the front.

Figure 7 : ReadyNAS NV Write performance - 100Mbps
(click image to enlarge)

The transfer rates well in excess of 100M Ethernet speeds show the effects of write caching. The results are similar to those obtained with the ReadyNAS 600, but with peak cached speeds actually a bit lower for the NV.