dump(5)
Name
dumprestor, dumpdates − incremental dump format
Syntax
#include <sys/types.h>
#include <sys/inode.h>
#include <dumprestor.h>
Description
Tapes used by dump and restore 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 described in the next list.
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(.).
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 nonzero. 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(.).
id_ddate The date of the incremental dump in system format. For further information, see types(.).
Files
/etc/dumpdates