Server performance and NAS devices

If performance when accessing VOBs whose databases are stored on a NAS device degrades significantly, move the VOB database to the VOB server host.

When a VOB or view server uses a NAS device for some or all of its VOB or view storage (see DevOps Code ClearCase and network-attached storage devices), any other uses of the device should be eliminated or minimized.

If the NAS device is used by other applications or provides storage for files and directories that are not part of VOB or view storage, the additional load these uses create on the device’s I/O subsystem can have a significant negative impact on DevOps Code ClearCase operations that access the VOB and view storage directories. This impact is especially severe when the whole VOB (database and pools) is stored on the NAS device.

If a VOB server must share a NAS device with other uses, keep the VOB database on the server itself, and locate just the pools on the NAS device. (This configuration is supported only for hosts running Linux® or the UNIX system.)

Note: Because of the additional network traffic required by the CIFS (SMB) protocol, Windows® VOB server hosts are the most likely to suffer degraded performance when they locate the VOB database on a NAS device.