bootchart--software to detect Linux boot performanceexcerpt fromHttp://www-128.ibm.com/developerworks/library/l-boot-faster/index.html?ca=dgr-lnxw01FC-FastLinuxBoot,
Parallelize applications for faster Linux booting, interested to read the original. You can also download the software directly from the http://www.bootchart.org/.
BOOTCHARTD is initialized in Init as a deamon, and then the control is returned to the INIT process. BOOTCHARTD sampling the system environment once every time, the default is 200ms, including CPU,I/O, idle time, disk usage, And the information of each activity process is obtained through proc, and the data is stored in/var/log/bootchar.tgz for later data analysis.
Monitoring init performance with Bootchart
As you change the landscape of the system boot process, it's useful to understand what changed and how it affects the O Verall time to boot. Ziga Mahkovec has built a very useful tool called Bootchart
to Visualize The makeup of the boot pro Cess. This tool consists of several elements, including a data logger utility and a visualization utility.
The data logger ( BOOTCHARTD
) runs in the place of the init
process (Usually, speci Fied in the grub or lilo.conf files). after bootchartd
has initialized, it surrenders control back to the real Init
process (typically,/sbin/init). BOOTCHARTD
is essentially a profiler that samples the environment at a periodic interval (by default, on Ce every MS). by sampling the environment, i mean that it reads the current CPU statistics, I/O and idle times, disk Usage, and information about every active process (through the proc
file System). This data was stored in a temporary file (/var/log/bootchart.tgz) for later post-processing.
Bootchart
Then uses a post-processing tool to transform the raw data into a boot chart. This process can occur locally using a java™application (part of bootchart
the distribution), but an easier method is through A Web form located at the bootchart
home page. An example piece of a boot chart was shown in Figure 2. Note that these charts tend to is quite large (depending on the services and applications started). For links to complete examples, seeresources.
bootchart--software to detect Linux boot performance