Backup and upgrade of running programs

[Volker Wysk]

Am Dienstag, 1. Januar 2019, 08:12:13 CET schrieb Nils Kassube:
> Volker Wysk wrote:
> > There's something that has troubled me for a long time. When you make
> > a backup, or do an upgrade, what happens when the affected programs
> > or data are still running or in use? Wouldn't this mean trouble?
> > 
> > Wouldn't it leave the system, or the backup, in an inconsistent state?
> 
> No. The program that is still running is the executable program and the
> libraries which were installed at the time the program was started, i.e.
> before the upgrade. This is still running in the RAM of the machine,
> while the executable and libraries on the disk may be a new version
> already. Only if you want to use the new version of the upgraded
> program, you have to restart it.

Yes, but see the other mail.

> I'm not sure about backups though. I suppose there it depends on the
> backup program if you could get troubles.

I think backups are more problematic than upgrades. When backing up the data 
of some service, while it is running, you get a (hopefully consistent) image 
of one point in time of the service. This might not be a correct state to 
start it up from, again.

When I imagine to restore Akonadi from a backup, which has been taken while 
Akonadi was running, I get a stomach ache...

Cheers
Volker