MirBSD manpage: dump(5)
DUMP(5) UNIX Programmer's Manual DUMP(5)
dump, dumpdates - incremental dump format
#include <sys/types.h>
#include <sys/inode.h>
#include <protocols/dumprestore.h>
Tapes used by dump and restore(8) 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
<protocols/dumprestore.h> is:
#define NTREC 10
#define MLEN 16
#define MSIZ 4096
#define TS_TAPE 1
#define TS_INODE 2
#define TS_BITS 3
#define TS_ADDR 4
#define TS_END 5
#define TS_CLRI 6
#define MAGIC (int) 60011
#define CHECKSUM (int) 84446
#ifndef DUMPRESTORE_DEFINE_SPCL
extern
#endif
struct spcl {
int c_type;
time_t c_date;
time_t c_ddate;
int c_volume;
daddr_t c_tapea;
ino_t c_inumber;
int c_magic;
int c_checksum;
struct dinode c_dinode;
int c_count;
char c_addr[BSIZE];
} spcl;
struct idates {
char id_name[16];
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char id_incno;
time_t id_ddate;
};
#define DUMPOUTFMT "%-16s %c %s" /* for printf */
/* name, incno, ctime(date) */
#define DUMPINFMT "%16s %c %[^\n]\n" /* inverse for scanf */
NTREC is the number of 1024 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
filesystem 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 filesystem was dumped from.
c_volume The current volume number of the dump.
c_tapea The current number of this (1024-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 filesystem; see fs(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 filesystem, otherwise the char-
acter is non-zero. If the block was not present
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on the filesystem, 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 in the file
/etc/dumpdates 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(8).
id_ddate The date of the incremental dump in system format
see types(5).
/etc/dumpdates
dump(8), restore(8), fs(5), types(5)
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