SYNOPSIS
fatrace [ OPTIONS ]
DESCRIPTION
fatrace reports file access events from all running processes.
It does not report file access by fatrace itself, to avoid logging events caused by writing the output into a file. It also ignores events on virtual and kernel file systems such as sysfs, proc, and devtmpfs.
Its main purpose is to find processes which keep waking up the disk unnecessarily and thus prevent some power saving.
By default, events are reported to stdout. This will cause some loops if you run this tool in e. g. gnome-terminal, as this causes a disk access for every output line. To avoid this, redirect the output into a file.
OUTPUT FORMAT
A typical event looks like
-
rsyslogd(875): W /var/log/auth.log
compiz(1971): O device 8:2 inode 658203
The line has the following fields:
-
Process name. This is read from /proc/pid/comm, and might be abbreviated for
long process names.
-
Process ID
-
Event type: Open, Read, Write, or Close. Combinations
are possible, such as CW for closing a written file.
-
Affected file. In some cases the path and name cannot be determined, e. g.
because it is a temporary file which is already deleted. In that case, it
prints the devices' major and minor number and the inode number. To examine
such a process in more detail, you should consider using
strace(1).
If you specify the --timestamp option, the first field will be the current time.
OPTIONS
- -c, --current-mount
-
Only record events on partition/mount of current directory. Without this
option, all (real) partitions/mount points are being watched.
- -o FILE, --output=FILE
-
Write events to given file instead of standard output.
- -s SECONDS, --seconds=SECONDS
-
Stop after the given number of seconds.
- -t, --timestamp
-
Add timestamp to events. When this option is given once, the format will be a
human readable hour:minute:second.microsecond; when given twice, the timestamp
is printed as seconds/microseconds since the epoch.
- -p PID, --ignore-pid=PID
-
Ignore events for this process ID. Can be specified multiple times.
- -f TYPES, --filter=TYPES
-
Show only the given event types.
TYPES
is a list of
C, R, O, or W
with the above meanings.
E. g. use --filter=OC to only show open and close events.
- -C COMMAND, --command=COMMAND
-
Show only events for this command.
- -h , --help
-
Print help and exit.