$ nbackup -L empty30.fdb
$ cp empty30.fdb empty30.tmp
$ nbackup -N empty30.fdb

    Variable header data:
        Database backup GUID:   { 667FCC1E-EC6B-43FE-00BC-6E3E3A405B09 }
        Sweep interval:         20000
        *END*

$ nbackup -b  1  empty30.fdb empty.nbk1
time elapsed    2 sec
page reads      170
page writes     13
$ gstat -h empty.nbk1
Wrong ODS version, expected 12, encountered 24919

[root@oel64 15:13:53 fb30]$ isql -q
SQL> create database 'tmp.fdb'; commit;
SQL> quit;

[root@oel64 15:14:15 fb30]$ nbackup -b 0 tmp.fdb tmp.nbk0
time elapsed    0 sec
page reads      216
page writes     216
[root@oel64 15:14:24 fb30]$ gstat -h tmp.fdb | grep -i "backup guid"
        Database backup GUID:   {38C79658-07FB-4EFB-73AA-7AFAC896EFF4}

[root@oel64 15:14:29 fb30]$ nbackup -b 1 tmp.fdb tmp.nbk1
time elapsed    1 sec
page reads      12
page writes     11
[root@oel64 15:14:41 fb30]$ gstat -h tmp.fdb | grep -i "backup guid"
        Database backup GUID:   {716FA1D3-8105-455B-1F8B-6F23AEE587CC}

[root@oel64 15:14:45 fb30]$ nbackup -b 2 tmp.fdb tmp.nbk2
time elapsed    1 sec
page reads      11
page writes     10
[root@oel64 15:14:54 fb30]$ gstat -h tmp.fdb | grep -i "backup guid"
        Database backup GUID:   {43100235-4D09-4BED-C1BD-7B14663E7885}

[root@oel64 15:15:59 fb30]$ nbackup -L tmp.fdb
[root@oel64 15:16:08 fb30]$ nbackup -N tmp.fdb
[root@oel64 15:16:12 fb30]$ gstat -h tmp.fdb | grep -i "backup guid"
        Database backup GUID:   {F543FBC5-9F6A-4BC8-9D81-8ACB0621FFDB}