manual: improve the documentation about sqlite migration

Be more obvious that the legacy plain text cache is not supported while we still
support the migration to the sqlite format.

Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
This commit is contained in:
Nicolas Sebrecht 2017-05-22 08:41:11 +02:00
parent f37b97c61b
commit ac5cfb0e29

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@ -225,17 +225,17 @@ done this yet, do it :). See the 'folderfilter' section in 'offlineimap.conf'.
OfflineImap caches the state of the synchronisation to e.g. be able to determine
if a mail has been added or deleted on either side.
+
The historical status cache is a plain text file that writes out the complete
file for each single new message (or even changed flag) to a temporary file. If
you have plenty of files in a folder, this is a few hundred kilo to megabytes
for each mail and is bound to make things slow. The latest status cache
is sqlite. This saves plenty of disk activity. The sqlite engine and the Python
sqlite module must be installed. The historical plain status cache is not
supported anymore.
The historical status cache was a plain text file that was writing out the
complete file for each single new message (or even changed flag) to a temporary
file. If there was plenty of files in a folder this was bound to make things
slow. The latest status cache is sqlite. This saves plenty of disk activity.
+
If you switch the backend from plain to sqlite, you may want to delete the old
cache directory in '<metadata>/Account-<account>/LocalStatus' manually (the
sqlite cache stands in the 'LocalStatus-sqlite' folder).
The historical plain status cache is not supported anymore but migrating from a
very old installation using the plain text cache is still supported. In this
case, you may want to delete the old cache directory in
'<metadata>/Account-<account>/LocalStatus' manually (the sqlite cache stands in
the 'LocalStatus-sqlite' folder). First, make sure you have run the new version
of offlineimap for all your accounts so that the status cache was migrated.
4. Use quick sync.
+