partition full, recreating a tape device

[David Newman]

Greetings. This is regarding a FSBD 4.10-RELEASE system.

df -h shows the root file system is 109 percent utilized:

Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/aacd0s1a   126M   126M  -9.9M   109%    /

The culprit is a rewindable tape drive in /dev. It shows up as an ordinary 
file, not as a device (like the nonrewindable device, /dev/nsa1):

-rw-r--r--  1 root  wheel  83046400 Nov 20 01:02 /dev/nsa1
crw-r-----  1 root  wheel   14,  16 Nov 24 05:50 /dev/rsa1

Question: How do I correct this so that:

1. /dev/nsa1 shows up as a regular device; and
2. /dev/nsa1 doesn't fill up the filesystem

Many thanks.

Regards,
David Newman
Network Test