You must reboot your Linux box when your install a new kernel or update critical libraries such as libc. Both Debian and Ubuntu Linux can tell you if the system needs a reboot when you login to your box as root user.
| Tutorial requirements | |
|---|---|
| Operating system/app | Debian/Ubuntu Linux |
| Root privileges required | Yes |
| Difficulty | Easy (rss) |
| Estimated completion time | 5m |
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Find out if my Ubuntu/Debian Linux server needs a reboot
To know if your Debian or Ubuntu cloud VM/VPS needs a restart use the following commands. Directly login as follows:
$ ssh root@server1.cyberciti.biz
OR
$ ssh vivek@server1.cyberciti.biz
$ sudo -i
Sample outputs:
If the file /var/run/reboot-required exists, you get the above message. You can check it yourself by typing the cat command:
$ cat /var/run/reboot-required
Sample outputs:
*** System restart required ***
One can put some sort of code in shell startup file such as ~/.bashrc:
[ -f /var/run/reboot-required ] && cat /var/run/reboot-required |
OR use if command in your script or startup file:
if [ -f /var/run/reboot-required ] then echo "[*** Hello $USER, you must reboot your machine ***]" fi |
You must reboot the Linux server/desktop using reboot command:
$ sudo reboot
OR
$ sudo shutdown -r now
This method seems to only work on Ubuntu Linux.
How to use needrestart-session command to checks which daemons need to be restarted after library upgrades
The needrestart-session command check for processes need to be restarted in user sessions. You can grab it from upstream or install it using apt-get command/apt command:
$ sudo apt-get install needrestart
Sample outputs:
Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: linux-headers-4.4.0-78 linux-headers-4.4.0-78-generic linux-image-4.4.0-78-generic Use 'apt autoremove' to remove them. The following additional packages will be installed: libmodule-find-perl libmodule-scandeps-perl libproc-processtable-perl libsort-naturally-perl libterm-readkey-perl Suggested packages: needrestart-session | libnotify-bin The following NEW packages will be installed: libmodule-find-perl libmodule-scandeps-perl libproc-processtable-perl libsort-naturally-perl libterm-readkey-perl needrestart 0 upgraded, 6 newly installed, 0 to remove and 0 not upgraded. Need to get 140 kB of archives. After this operation, 539 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 libmodule-find-perl all 0.13-1 [10.2 kB] Get:2 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 libmodule-scandeps-perl all 1.20-1 [29.8 kB] Get:3 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 libproc-processtable-perl amd64 0.53-1build1 [33.1 kB] Get:4 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 libsort-naturally-perl all 1.03-1 [13.7 kB] Get:5 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 libterm-readkey-perl amd64 2.33-1build1 [27.2 kB] Get:6 http://mirrors.service.networklayer.com/ubuntu xenial/universe amd64 needrestart all 2.6-1 [25.6 kB] Fetched 140 kB in 0s (5,243 kB/s) Selecting previously unselected package libmodule-find-perl. (Reading database ... 117527 files and directories currently installed.) Preparing to unpack .../libmodule-find-perl_0.13-1_all.deb ... Unpacking libmodule-find-perl (0.13-1) ... Selecting previously unselected package libmodule-scandeps-perl. Preparing to unpack .../libmodule-scandeps-perl_1.20-1_all.deb ... Unpacking libmodule-scandeps-perl (1.20-1) ... Selecting previously unselected package libproc-processtable-perl. Preparing to unpack .../libproc-processtable-perl_0.53-1build1_amd64.deb ... Unpacking libproc-processtable-perl (0.53-1build1) ... Selecting previously unselected package libsort-naturally-perl. Preparing to unpack .../libsort-naturally-perl_1.03-1_all.deb ... Unpacking libsort-naturally-perl (1.03-1) ... Selecting previously unselected package libterm-readkey-perl. Preparing to unpack .../libterm-readkey-perl_2.33-1build1_amd64.deb ... Unpacking libterm-readkey-perl (2.33-1build1) ... Selecting previously unselected package needrestart. Preparing to unpack .../needrestart_2.6-1_all.deb ... Unpacking needrestart (2.6-1) ... Processing triggers for man-db (2.7.5-1) ... Setting up libmodule-find-perl (0.13-1) ... Setting up libmodule-scandeps-perl (1.20-1) ... Setting up libproc-processtable-perl (0.53-1build1) ... Setting up libsort-naturally-perl (1.03-1) ... Setting up libterm-readkey-perl (2.33-1build1) ... Setting up needrestart (2.6-1) ... |
You can run it as follows:
$ sudo needrestart
Sample outputs:
Scanning processes... Scanning linux images... Running kernel seems to be up-to-date. No services need to be restarted. No containers need to be restarted.
If restart needed you will be greeted as follows:
Once you are notified it will proceed to restart needed services and containers as follows on screen:
Scanning processes... Scanning candidates... Scanning linux images... Running kernel seems to be up-to-date. Restarting services using systemd... SET needrestart/ui-query_conts LXC nginx, LXC mariadb, LXC memcached, LXC apache
How to use checkrestart command to check which processes need to be restarted after an upgrade
You must install debian-goodies package:
$ sudo apt-get install debian-goodies
Sample outputs:
Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: dctrl-tools Suggested packages: debtags xdg-utils zenity The following NEW packages will be installed: dctrl-tools debian-goodies 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 120 kB of archives. After this operation, 495 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://mirrors.linode.com/ubuntu xenial/main amd64 dctrl-tools amd64 2.24-2 [59.1 kB] Get:2 http://mirrors.linode.com/ubuntu xenial/main amd64 debian-goodies all 0.64 [61.3 kB] Fetched 120 kB in 0s (8,002 kB/s) Selecting previously unselected package dctrl-tools. (Reading database ... 37626 files and directories currently installed.) Preparing to unpack .../dctrl-tools_2.24-2_amd64.deb ... Unpacking dctrl-tools (2.24-2) ... Selecting previously unselected package debian-goodies. Preparing to unpack .../debian-goodies_0.64_all.deb ... Unpacking debian-goodies (0.64) ... Processing triggers for man-db (2.7.5-1) ... Setting up dctrl-tools (2.24-2) ... Setting up debian-goodies (0.64) ...
Once installed run checkrestart command to check which processes need to be restarted after an upgrade:
$ sudo checkrestart
Sample outputs:
Found 27 processes using old versions of upgraded files (19 distinct programs) (15 distinct packages) Of these, 14 seem to contain systemd service definitions or init scripts which can be used to restart them. The following packages seem to have definitions that could be used to restart their services: varnish: 3490 /usr/sbin/varnishd 3704 /usr/sbin/varnishd vnstat: 3631 /usr/sbin/vnstatd denyhosts: 17426 /usr/sbin/denyhosts openssh-server: 3630 /usr/sbin/sshd irqbalance: 3675 /usr/sbin/irqbalance dbus: 3460 /usr/bin/dbus-daemon lighttpd: 3670 /usr/sbin/lighttpd nginx-core: 3683 /usr/sbin/nginx 3686 /usr/sbin/nginx 3685 /usr/sbin/nginx udev: 2139 /lib/systemd/systemd-udevd cron: 3465 /usr/sbin/cron accountsservice: 3531 /usr/lib/accountsservice/accounts-daemon php7.0-fpm: 9565 /usr/sbin/php-fpm7.0 12663 /usr/sbin/php-fpm7.0 3692 /usr/sbin/php-fpm7.0 9441 /usr/sbin/php-fpm7.0 rsyslog: 3467 /usr/sbin/rsyslogd memcached: 3636 /usr/bin/memcached These are the systemd services: systemctl restart accounts-daemon.service These are the initd scripts: service varnish restart service varnishncsa restart service varnishlog restart service vnstat restart service denyhosts restart service ssh restart service irqbalance restart service dbus restart service lighttpd restart service nginx restart service udev restart service cron restart service php7.0-fpm restart service rsyslog restart service memcached restart These processes (1) do not seem to have an associated init script to restart them: util-linux: 3650 /sbin/agetty 3648 /sbin/agetty
Check for kernel and libc
You can manually check for installed/updated package log:
$ grep installed /var/log/dpkg.log
$ grep upgrade /var/log/dpkg.log
$ tail -f /var/log/apt/history.log
OR
$ grep libc /var/log/dpkg.log
Sample outputs:
2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status unpacked libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status half-configured libc-bin:amd64 2.23-0ubuntu9 2017-06-20 01:11:15 status installed libc-bin:amd64 2.23-0ubuntu9
Or use the following grep command to find out if libc/linux-image (kernel) was installed recently:
$ grep -B1 libc /var/log/apt/history.log
$ grep -B1 linux-image /var/log/apt/history.log
Sample outputs:
Start-Date: 2016-09-09 18:50:28 Commandline: apt install linux-image-4.4.0-36-generic Install: os-prober:amd64 (1.70ubuntu3, automatic), linux-image-4.4.0-36-generic:amd64 (4.4.0-36.55), grub-common:amd64 (2.02~beta2-36ubuntu3.2, automatic), grub2-common:amd64 (2.02~beta2-36ubuntu3.2, automatic), grub-pc:amd64 (2.02~beta2-36ubuntu3.2, automatic), grub-pc-bin:amd64 (2.02~beta2-36ubuntu3.2, automatic), grub-gfxpayload-lists:amd64 (0.7, automatic), libfreetype6:amd64 (2.6.1-0.1ubuntu2, automatic)
Conclusion
You learned about various command to see if a host powered by Debian or Ubuntu Linux needs a reboot. See the following tutorials:
- Ansible reboot a Debian/Ubuntu Linux for kernel update and wait for it – How can I reboot a Debian or Ubuntu Linux server/host remotely using an Ansible playbook for kernel update and wait for it to come back again?
This entry is 1 of 3 in the Linux Reboot Tutorial series. Keep reading the rest of the series:
- Find out if my Ubuntu/Debian Linux server needs a reboot
- OpenSUSE install lsof package to get rid of 'zypper ps' errors
- Check if CentOS / RHEL needs a full reboot
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And don’t forget the byobu “reboot_required” statusbar notification!
Hi Vivek,
a small typo:
* section “Find out if my Ubuntu/Debian Linux server needs a reboot”
–> shell statements:
if [ -f /var/run/reboot-required ] then echo "[*** Hello $USER, you must reboot your machine ***]" fo <<<AFAIK “fi”
THX for all!
Thanks for the heads up!