Tag: compression

  • Ubuntu: How to use multiple cores with tar gzip compression

    Ubuntu: How to use multiple cores with tar gzip compression

      One thing you may have noticed when using the z switch with tar is that the compression can take some time! If you look at your CPU usage, though, you’ll notice that only one core is being utilised to compress the files. In a modern system 4 or 8 cores are common, meaning that…

  • Ubuntu: Using compression on your tape backups

    Ubuntu: Using compression on your tape backups

      If you have compressible data you may save space on you tapes by using compression; this comes at a cost of CPU cycles to do the compressing, which can often be a worthwhile tradeoff for a long-term backup. To do this is quite simple – add in the -z switch to your tar command.…

  • ZFS: How to change the compression level

    ZFS: How to change the compression level

    By default ZFS uses the lzjb compression algorithm; you can select others when setting compression on a ZFS folder. To try another one do the following:   sudo zfs set compression=gzip [zfs dataset]   This changes the compression algorithm to gzip. By default this sets it to gzip-6 compression; we can actually specify what level…

  • ZFS: How to check compression efficiency

    ZFS: How to check compression efficiency

      If you have enabled compression on a ZFS folder you can check to see just how much disk space you’re saving. Use the following command:   sudo zfs get all [poolname]/[folder] | grep compressratio   An example:   sudo zfs get all backup01/data | grep compressratio   returns the following:   backup01/data compressratio¬† 1.50x¬†…