Last night I just did a bare metal install of Ubuntu 9.04 (amd64) then brought up Asterisk 188.8.131.52. The configs for Asterisk had been used on the same box prior to the upgrade. The box also contains a Digium TDM card.
A short time later, I discovered that the box suddenly was running at 80% utilization and that Asterisk had ceased working. Looking at the process list, I found two programs consuming almost all available CPU resourses - DD and klog. My syslog, messages and kern.log files were megs in size and contained essentially garbage. Just prior to the race condition starting, however, were references to DAHDI:
Apr 25 17:17:57 ASTERISK kernel: [ 8020.982920] TDM PCI Master abort
Apr 25 17:17:57 ASTERISK kernel: [ 8020.982935] TDM PCI Master abort
Apr 25 17:17:57 ASTERISK kernel: [ 8020.982943] TDM PCI Master abort
I rebuilt and reconfigured both DAHDI and Asterisk, but the issue remains. It appears that Ubuntu’s handling of the PCI bus might be the issue.
Anyway, my suggestion for Ubuntu users out there is don’t upgrade to 9.04 on a mission critical box just yet…