Backup entire linux system with tar to the partition that mounted in system itself

Question

All of my operating systems are mounted on one partition, it's /dev/vda1.

Is there problem if I backup the entire Linux directory with this command

root@myOS:/# tar -cJpf /mnt/bax/myOS.tar.xz .

Basically I backup the entire system and save it on my second partition.

Where /mnt/bax has been mounted by /dev/vda2 (second partition).

I'm afraid that a recursive backup will happen, I mean since /dev/vda2 is mounted, does that mean a recursive backup will happen?

Answer 1

You probably don't want to back up mounted and pseudo filesystems. At least not /proc /sys /tmp, etc. So use --one-file-system plus you can add additional mounted filesystems if you want.

root@myOS:/# tar --one-file-system --acls --xattrs --numeric-owner -JpScf /mnt/bax/myOS.tar.xz . /media/additional-mounted-drive

Or you can use --exclude to ignore directories:

root@myOS:/# tar --acls --xattrs --numeric-owner --exclude=mnt --exclude=proc --exclude=sys --exclude=tmp -JpScf /mnt/bax/myOS.tar.xz .

Answer 2

I've used this one a few times. I RSYNC system to a local folder (other partition) and exclude. Then you and TAR compress it, if you want.

mkdir /backup1; time rsync -aAXv -h --exclude={/backup*,/dev,/home,/lost+found,/media,/mnt,/mnt2,/proc,/run,/sys,/tmp,/var/lib/lxcfs,/var/lib/lxd/unix.socket} / /backup1

Verify the excluded folders and add/remove what fits your system.

Then you can just TAR the backup1 folder.

tar czfp --rsyncable UbuntuServer1604.tar.gz ./backup1

OR install and use a parallel high compression codec like lbzip2 or a faster one like pgiz

apt install lbzip2 -y && time tar cf backup1.tar.bz2 ./backup1 --use-compress-program=lbzip2

I played around with just using TAR for backup but prefer RSYNC. TAR does have compression options like parallel 'lbzip2' and 'pigz':
small compressed file lbzip2 or fast with pigz -k; possible sync issues? lbzip4 if error debian?

Compressed TAR files is placed on the / but you should save to your choice of folder and make sure to add that to the exclude list.

apt install lbzip2 -y; sudo time tar cpf backup1.tar.bz2 --exclude={/backup*,/dev,/home,/lost+found,/media,/mnt,/mnt2,/proc,/run,/sys,/tmp,/var/lib/lxcfs,/var/lib/lxd/unix.socket} --use-compress-program=lbzip2 / 

apt install pigz -y; sudo time tar cpf backup3.pigz.tar.gz --exclude={/backup*,/dev,/home,/lost+found,/media,/mnt,/mnt2,/proc,/run,/sys,/tmp,/var/lib/lxcfs,/var/lib/lxd/unix.socket} --use-compress-program=”pigz -k” / 

Either way this is an easy way to add folders to exclude for live backups.

--exclude={/backup*,/dev,/home,/lost+found,/media,/mnt,/mnt2,/proc,/run,/sys,/tmp,/var/lib/lxcfs,/var/lib/lxd/unix.socket}