Relax and Recover(ReaR) / disaster recovery

        # on nfs server
        
        yum install -y nfs-utils
        
        mkdir -p /storage
        
        cat << EOF > /etc/exports
        /storage        *(fsid=0,rw,sync,no_root_squash,no_subtree_check,crossmnt)
        EOF
        
        cat /etc/exports
        
        # /storage        *(fsid=0,rw,sync,no_root_squash,no_subtree_check,crossmnt)  
        
        systemctl enable --now nfs
        
        systemctl disable --now firewalld
        
        # on target server
        
        yum install -y rear pstree nfs-utils
        
        cat << EOF > /etc/rear/local.conf
        OUTPUT=ISO
        OUTPUT_URL=nfs://192.168.203.134/storage
        BACKUP=NETFS
        BACKUP_URL=nfs://192.168.203.134/storage
        BACKUP_PROG_EXCLUDE=("${BACKUP_PROG_EXCLUDE[@]}" '/media' '/var/tmp' '/var/crash')
        NETFS_KEEP_OLD_BACKUP_COPY=
        EOF
        
        rear -d -v mkbackup
        
        # on nfs server, new files created from target centos7 vm
        
        tree /storage
        
        # /storage
        
        # └── target-centos7
        
        #     ├── backup.log
        
        #     ├── backup.tar.gz
        
        #     ├── README
        
        #     ├── rear-target-centos7.iso
        
        #     ├── rear-target-centos7.log
        
        #     ├── selinux.autorelabel
        
        #     └── VERSION
        
        # now destroy the target centos vm, and recreate a new one
        
        # boot the new vm using rear-target-centos7.iso