Appendix E.1 Creating an input file on fixed-length blocked tape

Organization of this subsection
(1) Principal media
(2) File name examples
(3) Overview
(4) Creation examples

(1) Principal media

CMT,AT

(2) File name examples

/dev/cmt00 (internal CMT), /dev/sysdat (internal DAT)

(3) Overview

The length of a fixed-length blocked tape is an integer multiple of 512-byte blocks. Because management information is not recorded on the medium, only 512-byte integer multiples of data can be handled. Therefore, this medium cannot handle binary format.

Files in DAT format are handled by padding the unused portion of the last block with 0x00 (0x00 is not normally found in DAT-format files).

(4) Creation examples

(a) Regular file to fixed-length blocked tape

Copy DAT-format file '/etc/csh.login' to CMT internal tape '/dev/cmt00':

dd if=/etc/csh.login of=/dev/cmt00 conv=sync
[Figure] 5+1 input records
[Figure]6+0 output records

[Figure]System output

Explanation:
5+1 indicates that five 512-byte blocks and one block with fewer than 512 bytes are to be input.
6+0 indicates that six 512-byte blocks are to be output (the last block is padded with 0x00).