dump(5)
NAME
dump, dumpdates − incremental dump format
SYNTAX
#include <sys/types.h>
#include <sys/inode.h>
#include <dumprestor.h>
DESCRIPTION
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 <dumprestor.h> is:
#define NTREC 10
#define MLEN 16
#define MSIZ 4096
#define TS_TAPE 1
#define TS_INODE2
#define TS_BITS 3
#define TS_ADDR 4
#define TS_END 5
#define TS_CLRI 6
#define MAGIC (int) 60011
#define CHECKSUM(int) 84446
structspcl {
intc_type;
time_tc_date;
time_tc_ddate;
intc_volume;
daddr_tc_tapea;
ino_tc_inumber;
intc_magic;
intc_checksum;
structdinodec_dinode;
intc_count;
charc_addr[BSIZE];
} spcl;
structidates {
charid_name[16];
charid_incno;
time_tid_ddate;
};
#defineDUMPOUTFMT"%-16s %c %s"/* for printf */
/* name, incno, ctime(date) */
#defineDUMPINFMT"%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 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 (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 file system. For further information, 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 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 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. For further information, see dump (8).
id_ddate The date of the incremental dump in system format. For further information, see types(5).
FILES
/etc/dumpdates