DUMP

Section: File Formats (5)
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NAME

dump, ddate - incremental dump format  

SYNOPSIS

#include <sys/types.h>
#include <sys/ino.h>
# include <dumprestor.h>  

DESCRIPTION

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:


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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 words.

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
TS_INODE
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 is.
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.
CHECKSUM
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.
c_inumber
The number of the inode being dumped if this is of type TS_INODE.
c_magic
This contains the value MAGIC above, truncated as needed.
c_checksum
This contains whatever value is needed to make the record sum to CHECKSUM.
c_dinode
This is a copy of the inode as it appears on the file system; see filsys(5).
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 tapemark.

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 types(5).
 

FILES

/etc/ddate  

SEE ALSO

dump(1), dumpdir(1), restor(1), filsys(5), types(5)


 

Index

NAME
SYNOPSIS
DESCRIPTION
FILES
SEE ALSO

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