Incremental backup using tar : good for file system backup/archiving of log directories etc.
Commands: I am using LVL variable to ease my work in rewriting incremental backup. Start from 0 and go up from there.
export LVL=0
tar --verbose --create --file=tmp_${LVL}.tar --listed-incremental=tmp.snar tmp/*
Note: snar file remains same at all levels, it is the tracker for incremental changes.
Next just change LVL=1,2 ..... so on. Must or the tar file get overwritten.
If any of the files get changed or new file created, next level automatically picks it up.
Alternate Method(I prefer):See the variable --level (0 means base and the incrementals)
export LVL=1
tar --verbose --create --file=tmp_${LVL}.tar --listed-incremental=tmp.snar --level=${LVL} tmp/*
