Chapter 5 Best Practices
Selecting GoVault Cartridges
GoVault™ Data Protection Software, Version 1.0 User’s Guide
113
Data Set Size
Considerations
5
In most cases, selecting a cartridge size that is approximately equal to the
total size of the data set will be adequate to protect a data set with a
normal mix of fixed and dynamic file content, and without a high
concentration of noncompressible files.
In these situations, for example, selecting an 80 Mbyte GoVault cartridge
to protect an 80 Mbyte data set would support an initial backup of the
entire data set, and then daily backups for several months before
approaching the capacity of the cartridge.
Data Set Makeup
Considerations
5
On average, an initial baseline backup provides a data compression ratio
of approximately 2:1, taking about 40 Gbytes of disk space to back up 80
Gbytes of data. Subsequent backups, however, only compress and store
any new data and the portion of the original set that has changed since
the prior backup.
If you mostly make changes to existing files, or if you have multiple
folders with duplicate copies of the same file, then multiple backups over
a period of time can produce a virtual data compression ratio of 20:1 or
more.
If you mostly add new files, and seldom modify existing files, then the
net data compression ration will remain closer to the original 2:1, overall.
When selecting GoVault cartridges, always evaluate the makeup of the
data set you need to protect, and select a larger cartridge size if you have
a high proportion of already-compressed files, or if you more frequently
add new files than modify existing files.
Cartridge Rotation
Considerations
5
Using multiple cartridges to store your valuable data is a best practice,
and is vital to your data protection scheme.
In its simplest form, cartridge rotation would consist of a second GoVault
cartridge with a second copy of your baseline system archive that you
would store in a safe place at a different location. On a regularly
Note:
The term fixed files refers to files like video, music, pictures,
and so on. Once created, they are seldom changed or edited.
The term dynamic files refers to files like word processing
documents, spreadsheets, project plans, presentations, and so
on. They are frequently revised and updated.
