DUMP(5) File Formats Manual DUMP(5)
dump, ddate - incremental dump format
# include <<dumprestor.h>>
Tapes used by dump and restor(1) contain:
a header record
two groups of bit map records
a group of records describing directories
a group of records describing files
The format of the header record and of the first record of each
description as given in the include file <dumprestor.h> is:
NTREC is the number of 512 byte records in a physical tape block. MLEN
is the number of bits in a bit map word. MSIZ is the number of bit map
The TS_ entries are used in the c_type field to indicate what sort of
header this is. The types and their meanings are as follows:
TS_TAPE Tape volume label
A file or directory follows. The c_dinode field is a copy of
the disk inode and contains bits telling what sort of file this
TS_BITS A bit map follows. This bit map has a one bit for each inode
that was dumped.
TS_ADDR A subrecord of a file description. See c_addr below.
TS_END End of tape record.
TS_CLRI A bit map follows. This bit map contains a zero bit for all
inodes that were empty on the file system when dumped.
MAGIC All header records have this number in c_magic.
Header records checksum to this value.
The fields of the header structure are as follows:
c_type The type of the header.
c_date The date the dump was taken.
c_ddate The date the file system was dumped from.
c_volume The current volume number of the dump.
c_tapea The current number of this (512-byte) record.
The number of the inode being dumped if this is of type
c_magic This contains the value MAGIC above, truncated as needed.
This contains whatever value is needed to make the record sum
c_dinode This is a copy of the inode as it appears on the file system;
c_count The count of characters in c_addr.
c_addr An array of characters describing the blocks of the dumped
file. A character is zero if the block associated with that
character was not present on the file system, otherwise the
character is non-zero. If the block was not present on the
file system, no block was dumped; the block will be restored
as a hole in the file. If there is not sufficient space in
this record to describe all of the blocks in a file, TS_ADDR
records will be scattered through the file, each one picking
up where the last left off.
Each volume except the last ends with a tapemark (read as an end of
file). The last volume ends with a TS_END record and then the tape-
The structure idates describes an entry of the file /etc/ddate where
dump history is kept. The fields of the structure are:
id_name The dumped filesystem is `/dev/id_nam'.
id_incno The level number of the dump tape; see dump(1).
id_ddate The date of the incremental dump in system format see
dump(1), dumpdir(1), restor(1), filsys(5), types(5)