Tag: tar
-
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: How to add or append a file to an existing tape backup
Sometimes you may with to add files to an existing backup; if you issue a command like: tar -cvf /dev/st0 backupfiles …and the tape is not already set to the end of the previous archive you will over-write any data from the position on the tape. Use the “eom” command to move…
-
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.…
-
Ubuntu: Using tar to span a backup across multiple tapes
Following on from the article on writing files to a tape backup, what happens if you want to back up more than what fits on a single tape? Here we want to use the –multi-volume switch, or -M. Use it so: tar -cvMf /dev/[path-to-tape] [backup folder or files] As a working example:…