Startup Scenes
Charly's Column – systemd-analyze
In sys admin columnist Charly's case, no fumbled system startup goes undetected. This was already the case with SysVinit and has not changed with systemd. In terms of the his analysis tools, no stopwatch goes unturned.
If a distribution shows its splash screen on startup – and almost all of them do – then I turn it off as of the second boot. I want to see the kernel messages rushing by when booting. Because more often than you might think, there's a problem with booting. When I see something questionable scurry by, I search with a tool like Bootchart [1] to find and fix a hanging process or similar issues quickly.
On systems with systemd, this is also possible in principle, but the tool is different: systemd-analyze
. When called without parameters, systemd-analyze
calculates the elapsed time until system startup is completed, broken down into kernel and userspace processes:
Startup finished in 3.507s (kernel) + 16.334s (userspace) = 19.842s
Of course, I want to know more about those processes now. The command systemd-analyze blame
gives me a list of all processes started at boot time. They are sorted by the elapsed time before the process has fully launched. I usually only see the 10 biggest time hogs, as shown in Listing 1.
Listing 1
systemd-analyze blame | head
1min 3.753s apt-daily.service 40.702s apt-daily-upgrade.service 8.649s fail2ban.service 4.246s networking.service 3.327s smokeping.service 2.622s apache2.service 2.303s mysql.service 2.206s postfix.service 1.835s dev-sdb1.device 993ms munin-node.service
In this particular case, I can ignore the candidates in lines 1 and 2 – they appear if the system performs unattended updates or upgrades on startup. Fortunately, they do not block any other processes and simply wriggle around a bit in the background. systemd-analyze
does not calculate them for this reason, as can already be seen from the sums.
Serial Plot
With the plot
parameter, I can create a kind of timeline in SVG format, which shows the boot process in a very clear graphical way. For this to work, the graphwiz package must be installed. The command is then:
systemd-analyze plot > systemd-boot.svg
Figure 1 shows a small section of the results. The start time of the individual processes is symbolized here by a red bar. Not only the start order and times, but all the dependencies between the services, can be summarized by the tool in the form of an SVG graphic:
systemd-analyze dot | dot -Tsvg > dependencies.svg
Caution: The result is really huge and probably only makes life easier for owners of A1-sized plotters.
Infos
- Bootchart: http://www.bootchart.org
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux Servers Targeted by Akira Ransomware
A group of bad actors who have already extorted $42 million have their sights set on the Linux platform.
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.
-
Kodi 21.0 Open-Source Entertainment Hub Released
After a year of development, the award-winning Kodi cross-platform, media center software is now available with many new additions and improvements.
-
Linux Usage Increases in Two Key Areas
If market share is your thing, you'll be happy to know that Linux is on the rise in two areas that, if they keep climbing, could have serious meaning for Linux's future.
-
Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs