Chapter 3: Operations

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•If Clear is specified, the port history buffer is cleared and all data is discarded at the end of a session.

•If Keep is specified, the port history buffer’s content is retained at the end of a session.

To clear and discard all data in a port history buffer:

Issue a Clear command while you are in port history mode.

CLEAR - or -

Issue a Server CLI command, indicating History=Clear.

SERVER CLI HISTORY=CLEAR

In this case, the port’s history buffer is cleared at the end of each device session.

NFS history files

When the NFS feature is enabled on the CCM appliance and on a port, port history data is written to a file on an NFS server, in addition to the local history buffer on the CCM appliance. Each serial port has its own file(s) on the NFS server where data is written. The NFS server must support NFSv3 (RFC1813).

Timestamps

Timestamps are written to the history file in the format: YYYY-MM-DD HH:MM:SS, where the hour (HH) is in 24-hour format. Each timestamp is preceded and followed by a carriage return and linefeed (CR+LF). The timestamp date/time uses the current time on the CCM appliance, which is assumed to be UTC (Universal Coordinated Time). You may display the current time on the CCM appliance at any time by entering a Show Server command.

A timestamp is inserted at the beginning of the file and whenever the file is opened for data to be written, but not more frequently than once every second.

If the CCM appliance is unable to send incoming data to the NFS server file quickly enough (for example, due to network load or server speed), an overrun may occur in the history accumulation buffer, and older data will be discarded to accommodate new incoming data. If this occurs, the location in the history file where the data was lost will indicate <<data lost due to overrun>> appended to the timestamp.

Enabling NFS on the CCM appliance

To use NFS, you must first enable NFS on the CCM appliance by identifying the address and mount point of the NFS server, plus the file type and the protocol.

NOTE: The NFS server’s system administrator must make the appropriate configuration changes to allow the CCM appliance to access a specific subdirectory in the NFS server’s file system (the mount point). This may or may not allow the CCM appliance to access and/or create subdirectories within the mounted subdirectory. This will affect what may be specified in the Port NFS command’s file parameter.