fertimmo.blogg.se - Tar xz create

Tar xz create archive#

So we’ve demonstrated that xz does indeed create much smaller archives than gzip.

Tar xz create archive#

But at 70 seconds, xz also took nearly 18 times as long! Compression levels six and beyond hugely increased the compression time for a negligible 1% reduction in archive size

With compression level 5, xz produced the smallest archive at 29 MB, which was 69% smaller than pig z.

delete Delete named files from the archive. d -diff -compare Find differences between files in the archive and corresponding files in the file system. (see notes below) -c -create Create a new archive (or truncate an old one) and write the named files to it. xz used compression level 1 out of 9 for this Note: This option requires a rewritable tarfile, tapes.

In the same 4 seconds, xz compressed the file to just 48 MB, which was 49% smaller than pigz.

Higher compression levels didn’t produce meaningfully smaller archives

At compression level 7 out of 9, pigz compressed the 818 MB CSV file down to 95 MB in 4 seconds.

pigz does this by default, xz because of the -T0 option

Both archiving tools saturated the CPU in our tests.

We compared xz to pigz, a gzip implementation that uses multithreading for faster compression and decompression.

To test this claim, we used the same 818 MB CSV file, and the same computer with six CPU cores and hyperthreading, as we used to test gzip in Linux. Previously, we stated that xz creates smaller archives than gzip.

Unlike xz, tar doesn’t delete the archive file after the extraction is completeĥ.

Because of the v option, tar shows which files are extracted from the archive.

tar does this automatically by inspecting the file and detecting the xz compression

We don’t have to tell tar to decompress with xz.

We decompress the file and extract its content into the current directory.

Please note that we removed the J option here because –use-compress-program already sets the compression program.ĭecompressing a tar archive with xz is also a single step and identical to gzip (except for the different file extension): tar xvf

Here, we specify the minimum compression level 1: tar cvf -use-compress-program='xz -1' *.csv We use this option to set the compression level, too. From man tar: -J, -xz Filter the archive through xz (1). Like so tar -cv /path/to/dir pixz -p4 > output.tpxz joelostblom. It is a great way to control the number of threads used for parallel compressing without having to create an intermediate. Tar allows setting the compression program through the –use-compress-program option. Note that tar can do all this for you, theres no reason to first create a tar archive and then compress it, you can create it compressed: tar -cJvf archive.tar file 1-5.txt That will produce . Modern versions of tar support the xz archive format (GNU tar, since 1.22 in 2009, Busybox since 1.17.0 in 2010). Which xz compression level does tar pick? It depends on our version of tar, but it probably is the default compression level 6. Unlike xz and gzip, tar doesn’t delete the input files after it creates the archive.Because of the v option, tar shows which files are added to the archive.The J option enables compression with xz.We compress all files with a csv extension in the current directory into the compressed archive,.