tdb questions

[Daniele Dario]

On Fri, 2013-05-24 at 15:41 +0200, Volker Lendecke wrote:
> On Fri, May 24, 2013 at 02:47:17PM +0200, Daniele Dario wrote:
> > thanks so much for the response.
> > 
> > The system power has a battery backup which gives us 3 min of power and
> > notify the application that line power has gone so I'm able to close all
> > handles but I can't perform a clean shut down to the system because if
> > power comes on again while it is shutting down I'm not able to restart
> > it. I need to completely remove power to terminate the shut down in
> > order to allow a (re)start. If line power comes up within the 3 min of
> > battery power, the application would be notified and re-open files.
> > 
> > Said this, would it be enough to use tdb_close when we loose line power
> > to keep tdbs safe?
> 
> Without transactions, no. You can never be sure the system
> has written the buffers to disk without fsync and barriers.
> 
> > About the FS actually it is an ext2 partition on a DiskOnModule so to
> > enable write barriers have to move to (at least) ext3 so I'll start
> > looking on that.
> 
> Ok, ext2. If that has met your persistence and recovery
> requirements, I think you don't have to bother with
> transactions at all. Just use tdbs without transactions and
> reinstall the system when it's hosed.
> 
> Volker
> 

Mh, the idea was to try with transactions but I'm still looking in the
sources of samba4 how to use them. Can you point me in the right
direction (or which would be the best place to look in)?

Daniele.