Develop backup strategy

We need to backup:

• dspace asset store (file system directory)
• space meta data db (postgres DB)
• dspace/handle store (postgres DB)

To this end, we need to get these tasks done first:

• Where put backups? (Onsite/Offsite; EUDAT; different ceph mount; different mount altogether...)
• How often put backups?
• Test backup and restore
• Document strategy in FAQ (cf #6 (closed))
• schedule re-test for restore