Archiving and Compression

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gzip

 

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tar (.tar) - Tape Archive

Take multiple files and compress them into a single file.

-c -create archive

-f -filename

-x -extract

-z -compress/decompress

-f -filename

Creating an archive (uncompressed)

tar -cf archivename.tar filestoarchive

Creating an archive (compressed)

tar -czf archivename.tar.gz filestoarchive

Extracting a tar archive (compressed)

tar -xzf archivename.tar.gz

Extracting a tar archive (uncompressed)

tar -xf archivename.tar

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DD - Convert and copy

Full disk backup

dd if=/dev/sda of=/pathtobackupfile.img

By default, dd will take the backup 1 block at a time - meaning it can take a while. We can add the 'bs' option to specify how much data dd should copy at a time.

dd if=/dev/sda of=/pathtobackupfile.img bs=1M

For sensitive copies, we can add the conv=sync flag to have dd compare the original data and the copy for 100% accuracy - this will take a lot longer.

dd if=/dev/sda of=/pathtobackupfile.img bs=1M conv=sync

Compression

We can also pipe the dd output into gzip for compression.

dd if=/dev/sda bs=1M | gzip -o > pathtobackupfile.gz

To uncompress:

gunzip pathtobackupfile.gz | dd of=/dev/sdc bs=1M

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xz (.xz) - 

cpio (.io) -