mmctl export create
or when using Yunohost Mattermost instance you first have to run
export MMCTL_LOCAL=true export MMCTL_LOCAL_SOCKET_PATH=/var/run/mattermost/mattermost_local.socket
then
sudo --preserve-env /var/www/mattermost/bin/mmctl export create
then
mmctl export list
(will display the name of the export file), for example
s9rbitior7f89namb6gfitcn8c_export.zip
then in this case
mmctl export download s9rbitior7f89namb6gfitcn8c_export.zip
Try to locate the file. I was using Yunohost, and there it was located it
/home/yunohost.app/mattermost/export
Offical documentation: https://docs.mattermost.com/manage/bulk-export-tool.html
upload the exported zip-file to the new server and import it
mmctl --local import s9rbitior7f89namb6gfitcn8c_export.zip
Check if the file was imported
mmctl import list available
It will show a new name of the zip-file
Process the uploaded file, this will take a few minutes and use lots of CPU if the file is big (mine was 780 MB)
mmctl --local import process c3yydbyfyty8jqky85zebcxb4o_65mzma97fjncbpyc8yytqnxr7o_export.zip
It will answer:
Import process job successfully created, ID: 11uedfiofpy1uf9okdr6mjc8ah
and then you will have to wait a few minutes. In my case it worked surprisingly well, only all the direct messages were marked as unread, but this is only a minor issue
Official documentation: https://docs.mattermost.com/onboard/bulk-loading-data.html