Tag Archives: centos

Advantures of CentOS 5.3 upgrade

I've upgraded my home server (which is also a router and an access point) from 5.2 to 5.3. All in all it was pretty flawless. Kudos to the CentOS team! Still, I'll update about few issues I've encountered:

1. Atheros wifi driver: I've been using the madwifi driver until now, which is not a part of the kernel because of licensing issues (contains proprietry firmware I guess). CentOS 5.3 introduced the ath5k driver, which is a free implementation. However, ath5k still doesn't implement "access point" mode, so I had to disable it (renamed  ath5k.ko and ran depmod -a), and reinstall madwifi 0.9.4 instead (simply running make; make install).

2. udev.rules were overwritten, which cleared the changes I've made, in particular the /dev/snd permissions were reverted to CentOS default (no "audio" group, only the device owner can access audio), so I had to re-change the /dev/snd/* file permissions.

glibc 2.7 on CentOS / RHEL 5

Update: Note! The issue was fixed in CentOS/RHEL 5.2 !

glibc 2.7 introduces a new flag to open() syscall, called O_CLOEXEC.

The official redhat 2.6.18 kernel (even of version 5.1) doesn't support it, and returns errors (in strace it looks like open() returns unknown error 530).

So.. just try not to use glibc 2.7 on RedHat, until they support it. If you want an adventure, this kernel seems to do the job..

How did I encounter this uncommon problem, you ask? I'm running Debian unstable VM inside a CentOS5 host (the VM's kernel is actually a CentOS5 kernel). Debian upgraded glibc to 2.7, and later the VM couldn't function (open /etc/passwd gave error 530). Not too smart of me, I guess. But dzickus kernel seems to solve it.