Empty backup directory

[Daniel]

On 2021-06-26 10:58, Kornel Benko wrote:
> Am Sat, 26 Jun 2021 09:29:29 +0200
> schrieb Daniel <xracoonx at gmx.de>:
> 
>> Hi,
>>
>> After installing LyX, the backup directory is empty (Preferences >
>> Paths). Does that mean that no backups are created by default or that
>> the backups are created even though "Backup documents, every ...
>> minutes" is checked (Preferences > Look & Feel > Document Handling)
>> (btw. Look & Feel seems a misnomer for backup settings). Or is a backup
>> created in the directory of the lyx file (the title bar shows a
>> directory even for new not yet saved files, so I suppose these files are
>> backup there as well)?
>>
>> Daniel
>>
> 
>  From what I understand, backups are created iff a lyx file changes while
> edited by lyx.
> 
> 	Kornel

I still find LyX's backups a bit confusing. Officially it says in the 
User Guide:

"Backup original documents when saving creates a backup copy of the file 
in the state when it was opened or when it was saved the last time. It 
is stored in the Backup directory (see section [sec:Paths]) or in the 
same folder as your document if no Backup directory is specified. The 
backup file has the file extension “.lyx~”.

With the option Backup documents, every, you can specify the time 
between backup saves.

Save documents compressed by default always saves files in a compressed 
format (see also section [subsec:Compressed]). This applies to newly 
created documents only. The compression status of existing documents is 
not changed when saving."

Sometimes there is a backup with the ".lyx˜" extension but sometimes 
with the ".lyx#" extension (as in "#filename.lyx#"). Contrary to the 
Guide, it seems as if the latter is the backup created automatically 
every 5 minutes by default. Also, they are not strictly speaking created 
every 5 minutes but only if in addition the document is the active one 
on LyX. That does not seem very safe.

Then I find the ".lyx~" files in my directories. I guess they are 
created when LyX crashes? And maybe also in the case that Kornel 
mentions, if I understood it correctly, i.e. when a document that is 
edited in LyX is changed (externally)?

It's all a bit confusing to me. Why are there different file 
extensions/names? Why does it periodically backup only when the document 
is active? What happens when LyX crashes with documents that have never 
been saved? Are there any backups created?

Daniel