T 2.57 Inadequate storage of media in the event of an emergency

If data need to be recovered following damage to an IT system, it is often necessary to copy the data backups first to separate storage media. This applies, in particular, to complex data structures such as databases, as the recovery of data here is not always a smooth and error-free process. If the available storage capacity is insufficient, a hasty reaction in during an emergency may result in an additional loss of data.

Example:

At a company running a large database application, the database management system (DBMS) indicated an inconsistency in the database. Thereby, the system management took the database out of operation and restored the most recent backup of the data in the production system. However, only the log and configuration files of the apparently corrupt database had been backed up. As a result of this action, all modifications of the data since the last backup were lost - an unknown error in the DBMS had prevented the recovery of these changes. A subsequent analysis of the log and configuration files showed that the database had, in fact, remained consistent. If sufficient disk space had been available, the old productive system could have been ready for operation again without any loss of data, following identification and elimination of the apparent inconsistency.