AIP Backup Compression

Common Compression Techniques

ActiveImage Protector uses two very common compression techniques: 1) Lempel-Ziv-Oberhumer (LZO) and 2) ZLIB (DEFLATE). LZO is used because of its speed and ZLIB is used because of its compression ratio. ActiveImage Protector uses highly optimized implementations of these algorithms in order to provide the fasted possible speeds for compression and decompression.

Lempel-Ziv-Oberhumer (Standard):

LZO offers moderate compression levels and slightly faster compression speeds over ZLIB. However, LZO decompression speeds are extremely fast. LZO is useful on older computers with fewer cores. LZO uses less CPU cycles for both compression and decompression. Desktop computers, laptop computers, and netbook computers can reduce CPU resource consumption by using LZO. On netbook and laptop computers, this can result in extended battery life as well as better performance for foreground applications during a backup.

Another, more specialized, use for LZO compression is for applications that mount ActiveImage Protector image files for file-level recovery. File-level recovery is not streamed data and thus is not a good candidate for using parallel speedup algorithms for compression and decompression. Because of the extremely fast decompression speeds of LZO, applications that require extensive file-level recovery can greatly benefit from LZO compression.

ZLIB (High):

ZLIB is encapsulations of the late Phil Katz's data compression algorithm DEFLATE. DEFLATE uses a combination of the LZ77 algorithms and Huffman coding algorithms. ZLIB provides greater compression ratios at the expense of CPU resources. It takes longer to compress a message using ZLIB, but the resulting message is smaller. ZLIB offers some tuning parameters to determine how much work the algorithm will do in order to compress the data. The less work the algorithm does, the less the compression ratio and the faster the compression time. ActiveImage Protector uses a fixed value of seven on a scale of one to nine. We have found that on a typical system volume, anything past seven starts to give diminishing levels of return on speed vs. compression ratio. For backups that are less frequently used, or for backups where the destination free-space is a limited resource, ZLIB is the recommended compression method.

Active Image Protector, utilizing highly optimized compression code written in assembly language, is the fastest image backup and disaster recovery product in the industry.

For the future, Rectiphy is developing new techniques to improve compression when working with known types of data. For example, disks that contain databases tend to have lots of text data. Text data is highly compressible as there are many repeating data patterns; less entropy. Rectiphy is working with block-sorting algorithms and arithmetic compressions algorithms that can have a significant impact for compression ratios on known types of data. Look for some of these new features down the road as we continue to innovate ways to better protect your data.