You can use tar command as usaul for making up backup. Generally tape device name is st0 under OpenBSD.
To find out tape device use dmesg command:
To dump /home file system located on /dev/sd0h (/dev/rsd0h) use dump command
Code:
dump -0au -f /dev/nrst0 /dev/rsd0h
0 = full backup
a = determine tape media length
u - Update the file /etc/dumpdates to record when backup was last created
-f /dev/nrst0 = tape name
/dev/rsd0h = partition name (use mount command to see all partition name
Rewind tape
Code:
mt -f /dev/rst0 rewind
To view tape contents use command
Code:
restore -tvs 1 -f /dev/rst0
1 indicates first partition. Use 2 for second parition and so on...
To restore use commad (let us say /home again)
Code:
cd /home
restore -rs 1 -f /dev/rst0
Go throuh man mt, dump and restore for more information.