Most of the undercloud disk space is used :

[root@instack ~]# df -h
Sys. de fichiers Taille Utilisé Dispo Uti% Monté sur
/dev/sda1           50G     49G  1,1G  99% /

After quick search, it seems to be from the keystone database.

MariaDB [keystone]> SELECT table_name AS "Tables", round(((data_length + index_length) / 1024 / 1024), 2) "Size in MB" FROM information_schema.TABLES WHERE table_schema = "keystone";
+------------------------+------------+
| Tables | Size in MB |
+------------------------+------------+
| access_token | 0.05 |
| sensitive_config | 0.02 |
...
| token | 2400.45 |
| trust | 0.02 |
+------------------------+------------+


[root@instack ~]# mysql -NB keystone -e "SELECT COUNT(*) FROM token"
268057