|Testing disaster recovery|
Asigra's Televaulting has only two main backup/restore components, DS-System and DS-Client. The DS-System software is the centralized repository for backups. This is how the bank deployed it: The DS-System contains the entire set of compressed and encrypted generations of incremental-forever backups from each remote location or laptop. All of the backed up data is stored as content-addressable storage. This means all of the compressed and encrypted files and/or data can be restored with a high degree of granularity. Individual files, complete volumes, database tables, complete databases or even bare metal can be restored from any of the backup generations. DS-System software runs on standard (Linux, Windows, Solaris or VMware) servers without any special hardware.
The DS-Client software is installed at remote sites. This part of the application collects the data to be backed up at the remote location from all of the target application, file, mail and database servers, as well as any included desktop and laptop PCs. The DS-Client maintains only the latest version of each backup; restores of that generation can be made locally without having to access the DS-System.
Multiple DS-Clients can transmit to the same central DS-System. DS-Client backup targets don't have agents; DS-Client uses standard APIs and existing security credentials to remotely log into all backup targets to capture relevant application data and securely manage the transfer to the DS-System.
The DS-Client maintains all current sets of permissions and doesn't require turning the backup targets into shared or mapped drives. It transmits all the data from first-time backups in a compressed and encrypted format to the central DS-System over a TCP/IP connection. It applies AES or DES encryption to backup data in flight and at rest in the DS-System repository. All subsequent target backups eliminate redundant (or common) files, and backs up incrementally or only the changed blocks (delta blocking). The net effect is that the bandwidth required at each remote site is measurably reduced, which is an important cost consideration for any distributed backup/restore program.
Cost was another key factor for the bank. DS-Client licenses are free, while the DS-System is licensed on a "pay-as-you-grow" basis based on the compressed backup capacity stored at the central location and additional advanced features. Essentially, the software is licensed the same way disk is purchased. The bank paid $90,000 MSRP with an ongoing OpEx of $27,000.
Of course, there's no such thing as a perfect implementation. Shortly after installing DS-Client, the bank discovered there wasn't enough memory in the system to collect the data. Doubling the RAM solved the problem.
The bank has deployed Televaulting on the majority of its servers and most of its desktops. It plans to roll it out to its remaining desktops and laptops. The results to date:
- Backup windows are no longer missed.
- Bandwidth requirements and WAN costs have declined by as much as 80%.
- Restores of individual files and SQL databases are completed in minutes.
- IT resources have been freed up.
- The reduction in DR costs has already paid for the solution.
- DR compliance is no longer a worry.
This was first published in May 2005