Inquisitor

EDAC is a generic name for technologies that do ECC memory monitoring and control in modern Linux kernels. We need to implement monitoring script that will support ECC memory checking / monitoring in Inquisitor.

Most modern Linux kernels support EDAC somehow, stability the same status as lm_sensors - i.e. declared as "unstable", but in practice, EDAC is widely supported by distro vendors and backported into a wide range of enterprise kernels. Looks like modern Linux EDAC monitoring works better than chipset-dependent memtest86+ ECC support, that always seems to be a 1-1.5 years behind the schedule.

A short list of relevant links about EDAC:

• http://bluesmoke.sourceforge.net/ - main site of the project, not a big deal; actively developed, all upcoming kernels are supported.
• http://buttersideup.com/edacwiki/ - brief, clear and concise introduction and tutorials.
• http://sourceforge.net/projects/edac-utils - project that hosts userspace utilities to support EDAC.

To make a long story short: EDAC is implemented as Linux kernel modules that should be loaded and configured. After that, they will:

• output errors in kernel's dmesg
• allow querying using sysfs interface (for control, accessing error counters/indicators, resetting, etc)

+ Therе are userspace utilites that can:

• edac-ctl - load necessary modules, autodetecting what's needed by CPU/processor (as sensors-detect in lm_sensors)
• edac-util - reads everything from sysfs interface and outputs in in ready-to-be-parsed manner (as sensors in lm_sensors)

Generally, to make this done, we'd need:

1. A kernel with full EDAC support; usually they're already in most modern kernels.
2. edac-utils installed in chroot.
3. Loading of necessary kernel modules during init (can be done using edac-ctl).
4. A monitoring script that wakes up every Nth second, checks if there are any errors and logs them to server.