Akonadi server won't start

[Martin Steigerwald]

David Jarvie - 19.08.21, 14:25:17 CEST:
> On Thursday, 19 August 2021 12:21:03 BST Ingo Klöcker wrote:
> > On Donnerstag, 19. August 2021 01:35:05 CEST David Jarvie wrote:
> > > On Tuesday, 17 August 2021 20:26:00 BST Ingo Klöcker wrote:
> > > > WARNING: Switching the database will make Akonadi forget more or
> > > > less
> > > > everything. Make a backup before proceeding. If you have lots of
> > > > filters configured, then export them before the switch. If you
> > > > have mail stored in
> > > > local folders, i.e. if you are not using IMAP exclusively, then
> > > > you
> > > > might
> > > > also want to export those folders. Akonadi may not have written
> > > > all
> > > > local
> > > > mail to local files so that some of those mails may only be
> > > > stored in
> > > > the
> > > > database.
> > > 
> > > I've already encountered the issue which you describe, i.e. that
> > > after moving mails from IMAP into local folders, no file is
> > > created in the directory for that folder. I've tried copying
> > > instead of moving, but that doesn't work either (unlike in older
> > > KDE PIM software).
> > 
> > Did you try copying single emails? This has always worked for me.
> > IIRC, then moving individual emails and copying multiple emails
> > also worked. Only moving multiple emails with a single operation
> > didn't result in files written to disk in some older version of
> > KMail. Dan fixed this problem quite some time ago. All of my
> > observations apply to maildir folders in my Local Folders.
> > 
> > Which version are you using?
> 
> I copied just a single email. I didn't try copying multiple ones.
> However, I just tried again today and moved first one email, and then
> two emails; both worked successfully (i.e. the files were saved in
> the directory). I'll have to keep an eye on this.

Another thing to consider: In case Akonadi is occupied with background 
activity like scanning a folder for new mails or changes the move or 
copy of the mail may take as long as this background activity takes to 
finish.

As to my observation which AFAIR has been confirmed by an Akonadi 
developer, maybe it was Dan, I do not recall exactly anymore, Akonadi 
simply is not able to do to things at once. It is not much of a problem 
for short term takes, but longer running tasks block out foreground user 
activity in KMail, sometimes without clear indication to the user what 
is going on.

Best,
-- 
Martin