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Lzip vs xz vs lzop2/1/2024 ![]() Together with an mtree listing (to capture some metadata that zpaq doesn't record) and some error recovery files (par2 or zfec), this makes a good archival solution, though I hesitate to call it perfect. That said, for long-term archival I wouldn't use any of the above: I prefer zpaq, which offers better compression than straight LZMA, along with dedup, journaling, incremental backup, append-only archives, and some other desirable features for archival. Yet, the lzip file format also has the advantages discussed in the article. Suffice it to say, the compression of the two files is comparable. An mtree file listing my home directory comes to 268 Mbytes uncompressed, resulting in an 81M lzip file and an 80M xz file (a difference of 720 Kbytes, less than 0.9% overhead). Just running some informal comparisons on my machine, an empty (zero byte) file results in a 36 byte lzip file and a 32 byte xz file, while my hosts file of 1346 bytes compresses to a 738 byte lzip file and a 772 byte xz file. When the article talks about shortcomings of the xz file format compared to the lzip file format, it's talking about file structure and metadata, not compression algorithm. Thus, the proposed benefits of the compression ratio apply equally to lzip as they do to 7z and xz. xz and lzip both accomplish the same goal, which is to store the LZMA-compressed stream while letting some other tool handle archival if desired, as is traditional on unixy systems, where archival is usually handled by tar (though you will sometimes fun into cpio or ar archives) while compression is handled by gzip (same compression algorithm as zip) or bzip2 or whatever else. 7z is akin to zip in that it functions as an archive in addition to the compressed data. The differences between them are in the container format that stores the data, not in the compression of the data. An mtree file listing my home directory comes to 268 Mbytes uncompressed, resulting in an 81M lzip file and an 80M xz file (a difference of 720 Kbytes, less than 0.9 overhead). 7z, xz, and lzip all use the same compression algorithm (LZMA).
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