Process accounting is a security method in which an administrator may keep track of system resources used, their allocation among users, provide for system monitoring, and minimally track a user's commands.
This indeed has its own positive and negative points. One of the positives is that an intrusion may be narrowed down to the point of entry. A negative is the amount of logs generated by process accounting, and the disk space they may require. This section will walk an administrator through the basics of process accounting.
Before making use of process accounting, it must be enabled. To do this, execute the following commands:
# touch /var/account/acct # accton /var/account/acct # echo 'accounting_enable="YES"' >> /etc/rc.conf
Once enabled, accounting will begin to track CPU stats, commands, etc. All accounting logs are in a non-human readable format and may be viewed using the sa(8) utility. If issued without any options, sa will print information relating to the number of per user calls, the total elapsed time in minutes, total CPU and user time in minutes, average number of I/O operations, etc.
To view information about commands being issued, one would use the lastcomm(1) utility. The lastcomm command may be used to print out commands issued by users on specific ttys(5), for example:
# lastcomm ls trhodes ttyp1
Would print out all known usage of the ls by trhodes on the ttyp1 terminal.
Many other useful options exist and are explained in the lastcomm(1), acct(5) and sa(8) manual pages.