* running more than one instance of FH

[jimlad68]

I have looked around but cannot find any definitive details on running more than one instance of FH.

I suspect that if 2 separate projects (or GEDCOM files) are open there is not a problem.

I have done some empirical testing of running more than one instance of FH on the same dataset, and I suspect that Ancestral sources effectively does that. What seems to happen is that FH notices the database (whatever/ wherever that is?) has been updated and prompts you to save the one you want. This of course can get messy, but presumably OK if you only use one of them for updating and the other for browsing.

But what about settings etc when running 2 instances.

[tatewise]

The database is the GEDCOM (.ged) file within the Project folder structure.
See how_to:v4:understanding_projects#project_structure|> Understanding Projects > Project Structure.

Customisations, settings, and preferences are a complex issue because some are per PC, some per User, and some per Project.
So it depends where the multiple FH instances are running - on same PC, in same User Account, or on same Project.
See how_to:understanding_scope_of_features|> Understanding the Scope of Features for details.

Another consideration is whether the various folders are shared via say Dropbox or OneDrive.

[jimlad68]

1. I understand that FH uses the project GEDCOM, just wondering how it kept track of it's multiple use. I'm suspecting that FH reads the GEDCOM into some sort of internal/temp database (Lua?), locks the GEDCOM file with some clever report back if opened again, then on completion overwrites the original GEDCOM.

2. So I think you imply re settings etc: Could be messy, or at least best not to mess with them if running more than one instance.

3. I do use the CLOUD (OneDrive + Copy.com), but purely for backups. You never know when the CLOUD will/not be there! Having said that, if I were multi "device" based I can see it being useful, although in my experience 2 way SYNCing is an easy way to loose/duplicate data!

[tatewise]

1. FH certainly reads the GEDCOM file into its internal memory (not Lua).
   It does not lock the file (otherwise nothing else could change it).
   I suspect it just monitors the Date modified to detect external changes.
   Whenever Save or Close is used FH overwrites the original GEDCOM file.
   Interestingly, AS uses a similar strategy.
2. Yes, it could get messy, changes in one FH instance might not migrate to another FH instance without closing and re-opening.
3. Many users do successfully use Dropbox, OneDrive, etc, not just for multiway syncing FH Projects but all their Documents.
   However, for the reasons you state, I would NOT rely on them alone for Backups.
   See glossary:backup_and_recovery|> Backup and Recovery.