Lziprecover is a data recovery tool and decompressor for files in the lzip
compressed data format (.lz), able to repair slightly damaged files,
recover badly damaged files from two or more copies, extract data from
damaged files, decompress files and test integrity of files.
The lzip file format is designed for long-term data archiving. It is clean,
provides very safe 4 factor integrity checking, and is backed by the
recovery capabilities of lziprecover.
Lziprecover is able to recover or decompress files produced by any of the
compressors in the lzip family; lzip, plzip, minilzip/lzlib, clzip and
Lziprecover makes lzip files resistant to bit-flip (one of the most common
forms of data corruption), and can safely merge multiple damaged backup
If the cause of file corruption is damaged media, the combination GNU
ddrescue + lziprecover is the best option for recovering data from multiple
If a file is too damaged for lziprecover to repair it, all the recoverable
data in all members of the file can be extracted with the '-D' option.
Lziprecover is able to efficiently extract a range of bytes from a
multi-member file, because it only decompresses the members containing the
Lziprecover can print correct total file sizes and ratios even for
When recovering data, lziprecover takes as arguments the names of the
damaged files and writes zero or more recovered files depending on the
operation selected and whether the recovery succeeded or not. The damaged
files themselves are never modified.
When decompressing or testing file integrity, lziprecover behaves like lzip
To give you an idea of its possibilities, when merging two copies, each of
them with one damaged area affecting 1 percent of the copy, the probability
of obtaining a correct file is about 98 percent. With three such copies the
probability rises to 99.97 percent. For large files (a few MB) with small
errors (one sector damaged per copy), the probability approaches 100 percent
even with only two copies.
Lziprecover is not a replacement for regular backups, but a last line of
defense for the case where the backups are also damaged.