Backup the file data/datastore.php
(by FTP or SSH). Restore by putting the file back in place.
Example command:
rsync -avzP my.server.com:/var/www/shaarli/data/datastore.php datastore-$(date +%Y-%m-%d_%H%M).php
To export links as an HTML file, under Tools > Export, choose:
Restore by using the Import
feature.
Example command:
./export-bookmarks.py --url=https://my.server.com/shaarli --username=myusername --password=mysupersecretpassword --download-dir=./ --type=all
If you export your bookmark from Diigo, make sure you use the Delicious export, not the Netscape export. (Their Netscape export is broken, and they don't seem to be interested in fixing it.)
See this issue for import tweaks.
To correctly import the tags from a SemanticScuttle HTML export, edit the HTML file before importing and replace all occurences of tags=
(lowercase) to TAGS=
(uppercase).