CDB boot error: CDB files corrupted

What are the possible reasons one might get corrupt cdb files error in ConfD-6.4.2

When trying to start ConfD one could encounter this error message (quoting the Advanced Topics -
Disaster Management):

  • “ConfD Fails to Start” chapter in the user guide:

“Exit code 15 means that A.cdb or C.cdb is corrupt in a non-recoverable way. Remove the files and re-start using a backup or init files.”

If ConfD crashes/is killed during a write to one of the journal files it should be OK, but if a disk/hard drive failure occurs happens during a schema upgrade of the C.cdb file it is likely that it will become corrupted since not all changes made to the schema could not be written to that file. In this case one need to apply a backup (which one of course created before starting the upgrade). If one have the CDB files at hand one can use the following command to see what ConfD thinks is corrupt:

confd --cdb-debug-dump Directory

Print a lot of information about the CDB files in Directory to stdout. This is a completely stand-alone feature and the only thing needed is the .cdb files (no running ConfD daemon or .fxs files etc).

If ‘–cdb-debug-dump’ works fine the CDB files should be OK.

Their are some cases where I copy the A.cdb and C.cdb and still it fails to come up. Below is what happens…

29-Aug-2017::11:26:09.692 confd[3572]: - Internal error: Supervision terminated

But when I remove the O.cdb things works fine. How to debug such cases ?.