How do I list or display all processes, executables, and shared libraries that are using up all virtual memory under Debian or Ubuntu Linux server for troubleshooting purpose?
Virtual memory is nothing but a memory management technique used by Linux and many other modern operating systems.
| Tutorial details | |
|---|---|
| Difficulty | Easy |
| Root privileges | Yes |
| Requirements | memstat tool |
It combines active RAM and inactive memory on disk drive (hard disk or ssd and so on) to form a large range of contiguous addresses. You can use the memstat command to see all processes, executables, and shared libraries that are using up virtual memory. This command must be run as root user as you need to see the data of all running processes. The output is intended to help you identify programs that are using an excessive amount of memory, and to reduce overall memory waste. The syntax is as follows:
memstat memstat -w memstat -p PID-HERE
The -w option causes a wide printout: lines are not truncated at 80 columns. The -p option causes memstat to only print data gathered from looking at the process with the given PID (such as an Apache process.
Examples
Type the following command:
# memstat
OR
$ sudo memstat
Sample outputs (from my home nfs server):
272k: PID 1 (/sbin/init)
536k: PID 467 (/sbin/udevd)
532k: PID 586 (/sbin/udevd)
276k: PID 1191 (/sbin/portmap)
296k: PID 1204 (/sbin/rpc.statd)
308k: PID 1222 (/usr/sbin/rpc.idmapd)
268k: PID 1385 (/usr/sbin/vnstatd)
91028k: PID 1424 (/usr/sbin/rsyslogd)
416k: PID 1473 (/sbin/mdadm)
1068k: PID 1493 (/usr/bin/atop)
464k: PID 1517 (/usr/sbin/atd)
404k: PID 1520 (/usr/sbin/rpc.mountd)
476k: PID 1530 (/usr/sbin/cron)
300k: PID 1539 (/usr/sbin/acpid)
560k: PID 1545 (/usr/sbin/sshd)
300k: PID 1550 (/usr/bin/dbus-daemon)
276k: PID 1568 (/sbin/getty)
78404k: PID 1606 (/usr/sbin/console-kit-daemon)
732k: PID 1755 (/usr/sbin/sshd)
2160k: PID 1760 (/bin/bash)
292k: PID 1807 (/usr/bin/ssh-agent)
532k: PID 1942 (/sbin/udevd)
776k: PID 1944 (/usr/sbin/pppd)
276k: PID 1945 (/bin/dash)
280k: PID 1948 (/usr/sbin/pptp)
280k: PID 1956 (/usr/sbin/pptp)
484k: PID 2369 (/usr/bin/memstat)
1280k( 1280k): /dev/zero 1755
1280k( 1280k): /dev/zero 1755
20k( 16k): /sbin/getty 1568
64k( 56k): /sbin/rpc.statd 1204
344k( 316k): /sbin/mdadm 1473
148k( 124k): /sbin/udevd 467 586 1942 467 586 1942 467 586 1942
40k( 36k): /sbin/init 1
24k( 20k): /sbin/portmap 1191
2136k( 88k): /lib/libgcc_s.so.1 1424
34932k( 48k): /lib/libnss_files-2.11.3.so 467 586 1204 1222 1424 1473 ...
2064k( 16k): /lib/libattr.so.1.1.0 1204
12388k( 76k): /lib/libresolv-2.11.3.so 1222 1545 1606 1755 1948 1956 1...
12404k( 92k): /lib/libpthread-2.11.3.so 1222 1424 1545 1550 1606 1755 ...
336k( 120k): /lib/ld-2.11.3.so 1 467 586 1191 1204 1222 1385 1424 147...
10288k( 28k): /lib/librt-2.11.3.so 1222 1424 1550 1606 1755 1222 1424 ...
18580k( 112k): /lib/libselinux.so.1 1 467 586 1530 1545 1550 1606 1755 ...
26704k( 28k): /lib/libnss_compat-2.11.3.so 467 586 1222 1424 1473 1517...
57108k( 1380k): /lib/libc-2.11.3.so 1 467 586 1191 1204 1222 1385 1424 1...
4360k( 248k): /lib/libdbus-1.so.3.4.0 1606 1755 1606 1755 1606 1755
12320k( 8k): /lib/libutil-2.11.3.so 1545 1568 1755 1944 1948 1956 154...
32916k( 84k): /lib/libnsl-2.11.3.so 467 586 1191 1204 1222 1424 1473 1...
10292k( 32k): /lib/libcrypt-2.11.3.so 1517 1530 1545 1755 1944 1517 15...
4124k( 20k): /lib/libnss_dns-2.11.3.so 1948 1956 1948 1956 1948 1956
2928k( 876k): /lib/libglib-2.0.so.0.2400.2 1606
4392k( 264k): /lib/libncurses.so.5.7 1493 1760 1493 1760 1493 1760
2064k( 16k): /lib/libuuid.so.1.3.0 1520
4108k( 12k): /lib/libcom_err.so.2.1 1545 1755 1545 1755 1545 1755
2172k( 112k): /lib/libblkid.so.1.1.0 1520
240k( 236k): /lib/libsepol.so.1 1
32904k( 8k): /lib/libdl-2.11.3.so 1 467 586 1222 1424 1493 1517 1530 ...
4624k( 512k): /lib/libm-2.11.3.so 1385 1493 1385 1493 1385 1493
26716k( 40k): /lib/libnss_nis-2.11.3.so 467 586 1222 1424 1473 1517 15...
2104k( 52k): /lib/security/pam_unix.so 1755
2056k( 4k): /lib/security/pam_nologin.so 1755
2064k( 16k): /lib/security/pam_limits.so 1755
2052k( 4k): /lib/security/pam_motd.so 1755
2052k( 4k): /lib/security/pam_deny.so 1755
2060k( 12k): /lib/security/pam_env.so 1755
2056k( 8k): /lib/security/pam_mail.so 1755
2052k( 4k): /lib/security/pam_permit.so 1755
2064k( 16k): /lib/libcap.so.2.19 1204
4104k( 8k): /lib/libkeyutils.so.1.3 1545 1755 1545 1755 1545 1755
2240k( 192k): /lib/libpcre.so.3.12.1 1606
10292k( 32k): /lib/libwrap.so.0.7.6 1191 1204 1520 1545 1755 1191 1204...
10288k( 48k): /lib/libpam.so.0.82.2 1517 1530 1545 1755 1944 1517 1530...
2056k( 8k): /lib/security/pam_ck_connector.so 1755
8k( 8k): /var/run/pppd2.tdb 1944
904k( 868k): /bin/bash 1760
104k( 100k): /bin/dash 1945
4252k( 148k): /usr/lib/libk5crypto.so.3.1 1545 1755 1545 1755 1545 1755
4316k( 204k): /usr/lib/libgssapi_krb5.so.2.2 1545 1755 1545 1755
2208k( 152k): /usr/lib/libexpat.so.1.5.2 1550
476k( 452k): /usr/sbin/sshd 1545 1755 1545 1755 1545 1755
108k( 100k): /usr/bin/ssh-agent 1807
12380k( 92k): /usr/lib/libz.so.1.2.3.4 1424 1493 1545 1606 1755 1807 1...
4132k( 28k): /usr/lib/libkrb5support.so.0.1 1545 1755 1545 1755
12k( 8k): /usr/bin/memstat 2369
44k( 40k): /usr/sbin/acpid 1539
2188k( 132k): /usr/lib/libpolkit-gobject-1.so.0.0.0 1606
120k( 112k): /usr/bin/atop 1493
4936k( 760k): /usr/lib/libkrb5.so.3.3 1545 1755 1545 1755 1545 1755
40k( 36k): /usr/sbin/cron 1530
24k( 20k): /usr/sbin/atd 1517
320k( 296k): /usr/sbin/rsyslogd 1424
2060k( 8k): /usr/lib/rsyslog/imuxsock.so 1424
2072k( 24k): /usr/lib/rsyslog/imklog.so 1424
2068k( 20k): /usr/lib/rsyslog/lmnet.so 1424
8116k( 1492k): /usr/lib/libcrypto.so.0.9.8 1545 1755 1807 1545 1755 1807
64k( 60k): /usr/sbin/vnstatd 1385
2260k( 208k): /usr/lib/libpcap.so.1.1.1 1944
2060k( 12k): /usr/lib/libck-connector.so.0.0.0 1755
2756k( 696k): /usr/lib/libgio-2.0.so.0.2400.2 1606
2064k( 16k): /usr/lib/libgthread-2.0.so.0.2400.2 1606
2332k( 276k): /usr/lib/libgobject-2.0.so.0.2400.2 1606
2060k( 12k): /usr/lib/libgmodule-2.0.so.0.2400.2 1606
2192k( 136k): /usr/lib/libdbus-glib-1.so.2.1.0 1606
2332k( 276k): /usr/lib/libeggdbus-1.so.0.0.0 1606
324k( 316k): /usr/bin/dbus-daemon 1550
136k( 132k): /usr/sbin/console-kit-daemon 1606
92k( 84k): /usr/sbin/rpc.mountd 1520
312k( 284k): /usr/sbin/pppd 1944
72k( 64k): /usr/sbin/pptp 1948 1956 1948 1956
32k( 20k): /usr/sbin/rpc.idmapd 1222
2152k( 100k): /usr/lib/libevent-1.4.so.2.1.3 1222
2076k( 24k): /usr/lib/libnfsidmap.so.0.3.0 1222
28k( 28k): /usr/lib/gconv/gconv-modules.cache 1530 1606 1760
2984k( 0k): /usr/lib/locale/locale-archive 1530 1760
2056k( 8k): /usr/lib/libnfsidmap/nsswitch.so 1222
--------
633108k ( 15844k)
Understanding the output
- First, the processes are listed. An amount of memory is shown along with a process ID and the name of the executable which the process is running. The amount of memory shown does not include shared memory: it only includes memory which is private to that process.
- After the processes, the shared objects are listed. The amount of memory is shown along with the filename of the shared object, followed by a list of the processes using the
shared object. - Finally, a grand total is shown.
Get data about Apache or Nginx or Lighttpd process only
First, find the pid of web-server:
# pidof httpd
# pidof nginx
# pidof lighttpd
Use the following syntax to only display data gathered from looking at the process with the PID # 3535
# memstat -p 3535
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| Category | List of Unix and Linux commands |
|---|---|
| Disk space analyzers | ncdu • pydf |
| File Management | cat |
| Firewall | Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04 |
| Network Utilities | NetHogs • dig • host • ip • nmap |
| OpenVPN | CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04 |
| Package Manager | apk • apt |
| Processes Management | bg • chroot • cron • disown • fg • jobs • killall • kill • pidof • pstree • pwdx • time |
| Searching | grep • whereis • which |
| User Information | groups • id • lastcomm • last • lid/libuser-lid • logname • members • users • whoami • who • w |
| WireGuard VPN | Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04 |
Can I see the same in FreeBSD, plz?
To combine the two commands presented on one line: memstat -p `pidof httpd`
For FreeBSD you should be able to find memstat with “find /usr/ports/ -name memstat” assuming that your ports tree is found in /usr/ports.
No, nothing:
19:32:03 [root@akira /usr/ports] # find /usr/ports/ -name memstat
19:33:00 [root@akira /usr/ports] # make search key=memstat
19:33:17 [root@akira /usr/ports] # make search name=memstat
19:33:31 [root@akira /usr/ports] #
FYI for those people looking, this package doesn’t exist in RHEL. It does exist in fedora but it’s for something completely different (memcached server/cluster). Too bad since that’s a nice tool.
As root run the following to build it on RHEL / Fedora / CentOS / SL or any other distro:
Note: you may have to adjust PATH settings in /etc/memstat.conf file.
Hope this helps!
Excellent Tool