Re: [Sks-devel] Keydump makes DB unavailable

[Phil Pennock]

On 2014-01-28 at 11:49 +0100, Frank de Bot wrote:
> I was trying to dump my keyserver database with 'sks dump 5000
> dump.new'. This goes well for a brief moment, but at a certain point my
> keyserver is unavailable and generates these errors:
> 
> <command handler> error in callback.: Bdb.DBError("BDB0060 PANIC: fatal
> region error detected; run recovery")
> 
> I already did db_recover53 n KDB and PTree, but it didn't helped.
> 
> Do I need to rebuild my database or is something else wrong?

The keyserver needs to be off-line while you dump.

The best approach is probably to have a filesystem which supports
snapshots, and do something like:

 1. shut down SKS
 2. db_recover (both KDB and PTree)
 3. db_archive (both KDB and PTree)
 4. take filesystem snapshot
 5. start up SKS
 6. mount filesystem snapshot elsewhere
 7. run `sks dump` from the snapshot
 8. delete the snapshot

That's off the top of my head, but I don't create dumps (my recovery
strategy is to use the dumps created by others and let SKS reconcile).
Those who do create dumps may be able to help refine this.

Perhaps we can add a wiki page enumerating a debugged list of steps?

If the DB areas have been recovered, so that the logs have been
replayed, does `sks dump` need the FS mounted read-write or would a
read-only mount work?  Are there still systems where snapshots can only
be mounted read-only, or is that now an entirely historical concern?
I know that FreeBSD UFS snapshots are mountable read-write and ZFS
snapshots can be used as the basis for a clone, which is read-write.

-Phil