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Re: Backup problem using "cp"




On Mon, 7 May 2018 09:59:01 -0400
Bob Weber <bobrweber@xxxxxxxxx> wrote:

> On 5/7/18 9:28 AM, 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. 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.)
> >
> >
> > Have a nice day :)
> >
> > Thomas
> >
> >  
> There is a program called rsnapshot that uses rsync for the actual
> work of copying but has a config file where you can supply exclude
> directories (like /media).  I just run "rsnapshot hourly" to copy my
> root file system before an apt upgrade command just in case a major
> problem occurs with the update.  The /proc /sys and /dev directories
> are not copied since they are "mounted" system directories.
> rsnapshot uses hard links between backups so only the changed files
> are actually copied.  The number of versions to keep is configured
> in /etc/rsnapshot.conf.
> 
> In using your cp command, rsync or rsnapshot it is very important
> that the destination filesystem be able to handle hard links and all
> the file attributes of a linux file system.  So make sure that at
> least there is an ext3 or ext4 type file system on the destination
> drive.  If you are not sure what file system is in use for the backup
> destination just run the mount command (as root) without any
> arguments and it will print out all the mounted file systems and
> types.

Another way to show fs type, without showing so much system stuff:

$ lsblk -f

This also shows labels (if any) and mount points.

 - Dan