Mirrored Servers

Mirrored Servers.  The BSI Mirrored Server™ addresses many of the deficiencies of tape backups.  In addition, it provides much additional functionality.  BSI Mirrored Servers are not just copies of your servers.  They deploy a versioning scheme so that you can recover the version of a file that was mirrored at a particular time.  Mirroring is sort of like doing an incremental backup with a detailed catalog of what files were backed up when.  Old copies are only deleted based on a user-defined aging policy.  The beauty of this is that files can be mirrored automatically at relatively high rates so that most saved changes to files are captured.  Excess copies are slowly deleted in a defined way.  For example, changed files can be mirrored every minute, then all but the last version of the day can be deleted every week, and every quarter all but the last version of the month can be deleted.  Other, more sophisticated, policies can be implemented based on the type of file, the server or directory on which it resides, etc.  

Local versus Remote.  Mirrored servers can be local or remote or both.  Typically, the mirroring schedule and the aging policy of a local mirrored server is different from a remote one.  Local mirrors are usually optimized for high performance in case it needs to be deployed as a file server when the primary file server goes down.  Remote mirrors are usually optimized to minimize the network bandwidth needed to access them. 

Archives.  Mirrored servers provide archiving, audit trails, and directories in addition to their backup and recovery functions.  The archival data and catalogs represent valuable company data that itself should be backed up.  In the case both local and remote mirrored servers are deployed, there is a duplicate copy of this data that will serve this purpose except for the unlikely possibility that both servers get simultaneously corrupted.    In any case, either full backups to tape or a redundant offsite mirrored server is recommended, both kept at a third, geographically distant, location. BSI provides at its remote storage sites, high-end tape archiving facilities for the use of its clients.  These archival copies are stored in fireproof and earthquake proof vaults at a geographically distant site.