gentoo server maintainance issues
12 jan 2011
motivation
this is the essence of the recent findings when doing server updates (on my two gentoo boxes).
in general: this is about: ‘emerge -uDN world’ and ‘emerge –depclean’.
system 1:
- i had serious problems with a failed glibcxx/gcc update. emerging qt-core failed with: /var/tmp/portage/x11-libs/qt-core-4.6.3/work/qt-everywhere-opensource-src-4.6.3/bin/qmake: /lib/libstdc++.so.6: version `GLIBCXX_3.4.11’ not found (required by /var/tmp/portage/x11-libs/qt-core-4.6.3/work/qt-everywhere-opensource-src-4.6.3/bin/qmake) FIX: the solution to this problem was quite adventurous: i applied a temporary hack from [1]: using libssp_simple.so and ld.so.preload. i was then able to recompile system (emerge -e system) and afterwards i could remove the preloaded library again.
system 2:
this update went pretty well compared to system 1 but it also failed horribly:
after the ‘emerge -uDN world’ update the system wasn’t able to start the /etc/init.d/net.eth0 service on reboot. this is because i used etc-update improperly and then /etc/modules.autoload.d/kernel-2.6 did not include the one kernelmodule i needed to be loaded. FIX: to avoid further module issues i decided to switch to genkernel using ‘make oldconfig’
as a result of using genkernel there were no /dev/hda or /dev/sda device nodes. i was able to added them manually using: mknod but after the reboot they were gone. FIX: see [2], a missing kernel configuration setting: CONFIG_SYSFS_DEPRECATED_V2=y but it should be disabled with =n, after a genkernel recompile & reboot it worked!
summary
two updates made two systems fail. that is why i hate to update in general. this isn’t an gentoo specific issue but a more general issue of the nature of updates. i always do my security updates but from time to time it is a good thing to do complete system updates. because services seem to degrade when they leave the ’time window’* they were designed for.
*the time window of a software (i define it) is a consequence of upstream/downstream using certain tools to build software. as the development cycle continues with more recent libraries/softwares, which is used by upstream, more recent components (dependencies) are pulled into the system. as a consequence: it is a good thing to use old programs with old libraries and recent programs with recent libraries. most often a mixture of both, old and new, leads to service degradation.