Proof of Existence of Document c3d357753826becf10b3

Note to the Public Internet Archive: I created a document, for which the sha256 is c3d357753826becf10b37830b59d476b18c4ec30d5159d17dcbc6da5aa1b38d1 This sha256 is recorded in the bitcoin blockchain with transaction 811cc32e2e20fe17a699d74e3e66b0b598f3a2bf6262f9efc657fa13021b9513

libtool: getting rid of 180,000 sed forks

When compiling systemd on rawhide, we noticed a significant slowdown in compile time. Investigating further, it turns out, that libtool forks an incredible amount of sed. Running perf showed 30% of the “make all” was spent in bash. strace showed an execve of sed with the same arguments 180,000 times!!!!! Looking in the code reveals […]

Single UEFI executable for kernel+initrd+cmdline

Lately Kay Sievers and David Herrmann created a UEFI loader stub, which starts a linux kernel with an initrd and a kernel command line, which are COFF sections of the executable. This enables us to create single UEFI executable with a standard distribution kernel, a custom initrd and our own kernel command line attached. Of […]


Self Hosting Fedora Base

If you want to bootstrap a distribution or want to rebuild it from the sources (SRPMS) to get the same binaries (think CentOS), you have to build the build tools and rebuild them with the built build tools, which have to be built with other build tools… My goal for a self-hosting Fedora Base is […]

Linux: HOWTO get the number of CPUs

$ getconf _NPROCESSORS_ONLN returns the number of CPUs online Internally it is parsing /sys/devices/system/cpu/online, which can have the contents: 0-3,5,7-9. Better let getconf do all the counting for you. This is very useful, if you want to optimize the number of threads.

Fedora Boot Optimization

This article shows how to reduce boot time for Fedora 17, but the recipe can also be applied to 18, 19 and 20. The target is to get a fast booting system with NetworkManager running and gdm displaying the login screen as fast as possible. The system I use here is a Lenovo T420s (2x2x […]

Redirecting apache access_log and error_log to the systemd journal

To redirect all apache messages to syslog, which will then appear in the systemd journal modify your httpd.conf: CustomLog “|/bin/logger -t access_log -p” “%v %h %l %u %t \”%r\” %>s %b \”%{Referer}i\” \”%{User-agent}i\”” ErrorLog syslog:user Of course it would be much nicer, if apache actually could use the journal directly. [Edit]: Apparently with apache […]



dracut – kernel command line

To quickly find out, what dracut wants as the kernel command for your current disk setup, fire up: # dracut –print-cmdline It will output something like: root=UUID=8b8b6f91-95c7-4da2-831b-171e12179081 rootflags=rw,relatime,discard,data=ordered rootfstype=ext4 This works for version 032 and newer.