ATOPACCTD(8) | System Manager's Manual | ATOPACCTD(8) |
atopacctd - process accounting daemon
atopacctd [-v | topdirectory]
The atopacctd daemon switches on the process accounting
feature in the kernel and let the process accounting records be written to a
file, called the source file from now. After process accounting is
activated, the atopacctd daemon transfers every process accounting
record that is available in the source file to a shadow file. Client
processes (like atop processes) will read the shadow files instead of
the process accounting source file.
In this way, the atopacctd daemon operates as a 'layer' between the
process accounting file that is written by the kernel and the shadow
accounting files that are read by atop processes.
This approach has the following advantages:
The directory /run is used as the default topdirectory.
Below this top-directory, the source file pacct_source is created to
which the kernel writes the process accounting records.
Furthermore, the subdirectory pacct_shadow.d is created as a
'container' for the shadow files. Apart from the shadow files, also the file
current is maintained in this subdirectory, containing the sequence
number of the current (newest) shadow file and the maximum number of records
that will be written in each shadow file.
An alternative topdirectory can be specified as command line argument. When an alternative topdirectory is defined, also modify the configuration file /etc/atoprc to inform atop clients about this alternative location (see the atoprc man page). Such alternative topdirectory should be owned by root and may not be writable for the group or others (security reasons).
Notice that the kernel suspends writing process accounting records
when the free space of the filesystem on which the process accounting file
resides drops below 2%. Writing is resumed when the free space is 4% or
more. These lowwater and highwater percentages can be configured via the
/proc/sys/kernel/acct pseudo-file.
The atopacctd daemon suspends transferring process accounting records
to shadow files when the free space of the filesystem on which the process
accounting file resides drops below 5%. Transfer is resumed when the free
space is 5% or more. Log messages are generated via syslog when writing to
the current shadow file is suspended or resumed.
The -v flag can be used to verify the version of the atopacctd daemon.
atop(1), atopsar(1), atoprc(5),
netatop(4), netatopd(8)
https://www.atoptool.nl
Gerlof Langeveld (gerlof.langeveld@atoptool.nl)
June 2018 | Linux |