An annoying and non-obvious rpmbuild “feature enhancement”

Specifically, under certain circumstances, it can dump debuginfo files into /usr/lib/debug and /usr/src/debug under your buildroot, neglect to build the corresponding -debuginfo package, and then have the gall to complain about the unpackaged files it dumped there. I have a confession to make: I’m anal-retentive enough about the systems I administer where I need to build RPM packages for everything so they can be easily updated, but I’m lazy enough where I usually just grab source RPMs out of the most recent Fedora repositories and modify the specfiles until they work on CentOS 5. This can lead to some interesting … Continue Reading →

Recording disk statistics with sysstat on RHEL/CentOS

Unlike on Debian-like systems, the default configuration for sysstat’s sa1 collector on RHEL/CentOS does not include disk statistics (like you would get from iostat) in the sa collection output. This is due to a missing flag in the cron.d fragment that calls sa1. The “-A” flag to sa1 defies reasonable assumption about its function, and does not include disk statistics, so we have to specify “-d” manually. To enable disk statistics collection/trending, edit /etc/cron.d/sysstat and change the following: */10 * * * * root /usr/lib64/sa/sa1 1 1 to this: */10 * * * * root /usr/lib64/sa/sa1 -d 1 1 (Obviously, … Continue Reading →

More on CentOS 5.3 to 5.4

So, here’s a humbling, humiliating and slightly funny follow-up to my last blog post: I’ve always done my due diligence in making sure upgrades go smoothly. As a result, I have a habit of tirelessly poring over release notes and the “known issues” section therein. However, I got burned this week when I failed to read all of the release notes. CentOS has a documentation page for the 5.0 series. And as of this writing, the documentation page links to a document called Release Notes. It does not, however, link to a completely different document that also is called Release … Continue Reading →

CentOS 5.3 to 5.4 upgrade woes

I’ve been pushing out CentOS 5.4 on a number of test systems this week, and I came upon a very interesting, very insidious, and very annoying problem. When running the upgrade, yum upgrade seems to run without a hitch, and returns completely successfully with no errors or warnings. However, what actually happens in the background is that the cleanup process breaks silently, and the package manager gets completely filled up with entries for duplicate packages that shouldn’t be allowed to coexist. I was alerted to the problem by rkhunter, which notified me during its post-reboot run that several files were … Continue Reading →