Saturday, February 7, 2015

Data Compression

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.