Data compression options are provided for data which is secured by
data protection operations. Generally speaking, compression is a very useful
way to reduce the quantity of data sent to storage, which will double the
effective capacity of the media in return (depending on the nature of the
data). Moreover, the system will automatically decompress the data and restore
it to the original state when the data is later restored or recovered.
The following data compression options are provided: software
compression and hardware compression. Software compression offers users to
compress data in the Client and MediaAgent while hardware compression for
libraries with tape media at the individual data path. In addition, as
compressed data often increases in size if it is again subjected to
compression, the system will apply one type of compression for a given data
protection operation. Therefore, users are able to redefine the compression
type at any time without damaging the ability to restore/recover the data.
If the hardware compression is available and applied, then it will
have some kind of priority over the other compression selections. Whenever
hardware compression has been enabled for a data path, all data conducted
through the data path will be compressed in the way of hardware compression
automatically. Otherwise, the data will be dealt with in accordance with the
software compression selection of each subclient which backs up to the data
path. Under such circumstances, people are able to choose from the following
options: Client compression, MediaAgent compression, or no compression.
Last but not least, bear in mind that hardware compression is not
applicable for disk libraries. As a result, the software compression selection
for subclient is adopted by people for data paths which are associated with
disk libraries. It is advisable to have a good understanding of such knowledge
before compressing data.
