StorNext File System Tuning
SNFS and Virus Checking
StorNext File System Tuning Guide 7
It can be useful to use a tool such as netperf to help verify network
performance characteristics.
SNFS and Virus Checking
Virus-checking software can severely degrade the performance of any
file system, including SNFS. If you have anti-virus software running on a
Windows Server 2003 or Windows XP machine, Quantum recommends
configuring the software so that it does NOT check SNFS.
The Metadata Network
As with any client/server protocol, SNFS performance is subject to the
limitations of the underlying network. Therefore, it is recommended that
you use a dedicated Metadata Network to avoid contention with other
network traffic. Either 100BaseT or 1000BaseT is required, but for a
dedicated Metadata Network there is usually no benefit from using
1000BaseT over 100BaseT. Neither TCP offload nor are jumbo frames
required.
It is best practice to have all SNFS clients directly attached to the same
network switch as the MDC systems. Any routing required for metadata
traffic will incur additional latency that impacts performance.
It is critical to ensure that speed/duplex settings are correct, as this will
severely impact performance. Most of the time auto-detect is the correct
setting. Some managed switches allow setting speed/duplex, such as
100Mb/full, which disables auto-detect and requires the host to be set
exactly the same. However, performance is severely impacted if the
settings do not match between switch and host. For example, if the switch
is set to auto-detect but the host is set to 100Mb/full, you will observe a
high error rate and extremely poor performance. On Linux the ethtool
tool can be very useful to investigate and adjust speed/duplex settings.