As part of the business continuity or disaster recovery, it is imperative for every organization to maintain a copy of its electronic data at an offsite location. Offsite backups can be maintained manually or through automatic means. When maintained manually, the backups are taken physically on media like tapes, magnetic discs etc at the onsite location and then transported to the offsite storage location. In an automatic offsite backup, there is no manual intervention involved and therefore is less error prone and can be done at more frequent intervals. Couple of automatic offsite backup solutions are listed below.
1. Electronic vaulting
a. Data is transmitted through communications line to a backup server / storage device at a different location
b. Data is transmitted on a batch mode at periodic intervals rather than an online basis.
c. Data backed up is a complete replica of the original data.
2. Remote journaling
a. Instead of the actual data only the transaction logs (journal / deltas / changes to individual files) are transmitted through communication line to a backup server at the alternate location.
b. Remote journaling is on online backup methodology.
c. Remote journaling is apt for database backup. When the production database is corrupted and requires a restoration, only the changes to database is required to be synched back.