dump(4) dump(4)
NAME
dump - incremental dump format
SYNOPSIS
#include <sys/types.h>
#include <sys/inode.h>
#include <protocols/dumprestore.h>
DESCRIPTION
Tapes used by dump and restore(4) 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
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];
char id_incno;
time_t id_ddate;
};
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dump(4) dump(4)
#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 ctype field to indicate
what sort of header this is. The types and their meanings
are as follows:
TSTAPE Tape volume label
TSINODE A file or directory follows. The cdinode
field is a copy of the disk inode and contains
bits telling what sort of file this is.
TSBITS A bit map follows. This bit map has a one bit
for each inode that was dumped.
TSADDR A subrecord of a file description. See caddr
below.
TSEND End of tape record.
TSCLRI 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 cmagic.
CHECKSUM Header records checksum to this value.
The fields of the header structure are as follows:
ctype The type of the header.
cdate The date the dump was taken.
cddate The date the file system was dumped from.
cvolume The current volume number of the dump.
ctapea The current number of this (1024-byte) record.
cinumber The number of the inode being dumped if this is
of type TSINODE.
cmagic This contains the value MAGIC above, truncated
as needed.
cchecksum This contains whatever value is needed to make
the record sum to CHECKSUM.
cdinode This is a copy of the inode as it appears on
the file system; see fs(5).
ccount The count of characters in caddr.
caddr 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
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dump(4) dump(4)
this record to describe all of the blocks in a
file, TSADDR 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 TSEND 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:
idname The dumped filesystem is /dev/idnam.
idincno The level number of the dump tape; see dump(1M).
idddate The date of the incremental dump in system format
see types(5).
FILES
/etc/dumpdates
SEE ALSO
dump(1M), restore(1M), fs(4), types(5).
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