| Chapter 6. System Monitoring Utilities | ||
|---|---|---|
 | Part II. Administration |  |
| Chapter 6. System Monitoring Utilities | ||
|---|---|---|
| | Part II. Administration | |
Contents
/proc File SystemAbstract
A number of programs and mechanisms, some of which are presented here, can be used to examine the status of your system. Also described are some utilities that are useful for routine work, along with their most important parameters.
For each of the commands introduced, examples of the relevant outputs are
presented. In these examples, the first line is the command itself (after
the > or # sign prompt). Omissions are indicated with square brackets
([...]) and long lines are wrapped where necessary. Line
breaks for long lines are indicated by a backslash (\).
# command -x -y
output line 1
output line 2
output line 3 is annoyingly long, so long that \
we have to break it
output line 3
[...]
output line 98
output line 99
The descriptions have been kept short to allow as many utilities as possible
to be mentioned. Further information for all the commands can be found in the
man pages. Most of the commands also understand the parameter
--help, which produces a brief list of the possible
parameters.
To view a list of all the files open for the process with process ID
PID, use -p. For example, to
view all the files used by the current shell, enter:
tester@linux:~> lsof -p $$ COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME bash 5552 tester cwd DIR 3,3 1512 117619 /home/tester bash 5552 tester rtd DIR 3,3 584 2 / bash 5552 tester txt REG 3,3 498816 13047 /bin/bash bash 5552 tester mem REG 0,0 0 [heap] (stat: No such \ file or directory) bash 5552 tester mem REG 3,3 217016 115687 /var/run/nscd/passwd bash 5552 tester mem REG 3,3 208464 11867 \ /usr/lib/locale/en_GB.utf8/LC_CTYPE bash 5552 tester mem REG 3,3 882134 11868 \ /usr/lib/locale/en_GB.utf8/LC_COLLATE bash 5552 tester mem REG 3,3 1386997 8837 /lib/libc-2.3.6.so bash 5552 tester mem REG 3,3 13836 8843 /lib/libdl-2.3.6.so bash 5552 tester mem REG 3,3 290856 12204 /lib/libncurses.so.5.5 bash 5552 tester mem REG 3,3 26936 13004 /lib/libhistory.so.5.1 bash 5552 tester mem REG 3,3 190200 13006 /lib/libreadline.so.5.1 bash 5552 tester mem REG 3,3 54 11842 \ /usr/lib/locale/en_GB.utf8/LC_NUMERIC bash 5552 tester mem REG 3,3 2375 11663 \ /usr/lib/locale/en_GB.utf8/LC_TIME bash 5552 tester mem REG 3,3 290 11736 \ /usr/lib/locale/en_GB.utf8/LC_MONETARY bash 5552 tester mem REG 3,3 52 11831 \ /usr/lib/locale/en_GB.utf8/LC_MESSAGES/SYS_LC_MESSAGES bash 5552 tester mem REG 3,3 34 11862 \ /usr/lib/locale/en_GB.utf8/LC_PAPER bash 5552 tester mem REG 3,3 62 11839 \ /usr/lib/locale/en_GB.utf8/LC_NAME bash 5552 tester mem REG 3,3 127 11664 \ /usr/lib/locale/en_GB.utf8/LC_ADDRESS bash 5552 tester mem REG 3,3 56 11735 \ /usr/lib/locale/en_GB.utf8/LC_TELEPHONE bash 5552 tester mem REG 3,3 23 11866 \ /usr/lib/locale/en_GB.utf8/LC_MEASUREMENT bash 5552 tester mem REG 3,3 21544 9109 \ /usr/lib/gconv/gconv-modules.cache bash 5552 tester mem REG 3,3 366 9720 \ /usr/lib/locale/en_GB.utf8/LC_IDENTIFICATION bash 5552 tester mem REG 3,3 97165 8828 /lib/ld-2.3.6.so bash 5552 tester 0u CHR 136,5 7 /dev/pts/5 bash 5552 tester 1u CHR 136,5 7 /dev/pts/5 bash 5552 tester 2u CHR 136,5 7 /dev/pts/5 bash 5552 tester 255u CHR 136,5 7 /dev/pts/5
The special shell variable $$, whose value is the
process ID of the shell, has been used.
The command lsof lists all the files currently open when used without any parameters. Because there are often thousands of open files, listing all of them is rarely useful. However, the list of all files can be combined with search functions to generate useful lists. For example, list all used character devices:
tester@linux:~> lsof | grep CHR bash 3838 tester 0u CHR 136,0 2 /dev/pts/0 bash 3838 tester 1u CHR 136,0 2 /dev/pts/0 bash 3838 tester 2u CHR 136,0 2 /dev/pts/0 bash 3838 tester 255u CHR 136,0 2 /dev/pts/0 bash 5552 tester 0u CHR 136,5 7 /dev/pts/5 bash 5552 tester 1u CHR 136,5 7 /dev/pts/5 bash 5552 tester 2u CHR 136,5 7 /dev/pts/5 bash 5552 tester 255u CHR 136,5 7 /dev/pts/5 X 5646 root mem CHR 1,1 1006 /dev/mem lsof 5673 tester 0u CHR 136,5 7 /dev/pts/5 lsof 5673 tester 2u CHR 136,5 7 /dev/pts/5 grep 5674 tester 1u CHR 136,5 7 /dev/pts/5 grep 5674 tester 2u CHR 136,5 7 /dev/pts/5
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| 5.6. For More Information |  | 6.2. User Accessing Files: fuser |