dump, dumpdates - incremental dump format

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SYNOPSIS

DESCRIPTION

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;
};

#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 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; 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; see dump.8

id_ddate

The date of the incremental dump in system format see types.5

FILES

SEE ALSO

Created by unroff & hp-tools. © somebody (See intro for details). All Rights Reserved. Last modified 11/5/97