On Mon 07 May 2018 at 15:28:14 (+0200), Thomas Schmitt wrote: > Hi, > > Richard Owlett wrote: > > My goal was to copy root and its sub-directory to a directory on another > > physical device. > > Well understood. > In a slightly different scenario (backup on Blu-ray) i do this several > times per day. > > But i would not dare to give the whole root tree as input to any copying > program or backup archiver.
I've cloned live systems in the past by writing: # cd / # find -xdev -path './lost+found' -prune -o -print | cpio -vdamp /mnt (omitting v to make it quieter). > Not only because of the risk of stepping on my > own foot but also because there are several trees which do not deserve > backup or could even make trouble when being fully read. > > In my root directory that would be: /dev /mnt /proc /run /sys > E.g. because of > $ ls -l /proc/kcore > -r-------- 1 root root 140737477877760 May 7 15:22 /proc/kcore > > (Somebody else shall try whether it's really readable and what comes out. > The announced size is nearly 128 TiB.) The -xdev (or cp -x) deals with those. Cheers, David.