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ufsdump(4)

Name | Synopsis | Description | Attributes | See Also

Name

ufsdump, dumpdates– incremental dump format

Synopsis

#include <sys/types.h>

#include <sys/inode.h>

#include <protocols/dumprestore.h>

/etc/dumpdates

Description

Tapes used by ufsdump(1M) and ufsrestore(1M) 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 the format of the first record of each description in the <protocols/dumprestore.h> include file are:

#define TP_BSIZE_MAX    65536
#define TP_BSIZE_MIN    1024
#define ESIZE_SHIFT_MAX 6 

#ifdef SUPPORTS_MTB_TAPE_FORMAT
#define TP_BUFSIZE      TP_BSIZE_MAX
#else
#define TP_BSIZE        1024
#define TP_BUFSIZE      TP_BSIZE
#endif /* SUPPORTS_MTB_TAPE_FORMAT */

#define NTREC           10
#define HIGHDENSITYTREC 32
#define CARTRIDGETREC   63
#define TP_NINDIR       (TP_BSIZE_MIN/2)
#define TP_NINOS        (TP_NINDIR / sizeof (long))
#define LBLSIZE         16
#define NAMELEN         64

#define OFS_MAGIC       (int)60011
#define NFS_MAGIC       (int)60012
#define MTB_MAGIC       (int)60013
#define CHECKSUM        (int)84446

union u_data {
        char    s_addrs[TP_NINDIR];
        int32_t s_inos[TP_NINOS];
};

union u_shadow {
        struct s_nonsh {
                int32_t c_level;
                char    c_filesys[NAMELEN];
                char    c_dev[NAMELEN];
                char    c_host[NAMELEN];
        } c_nonsh;
        char    c_shadow[1];
};

union u_spcl {
        char dummy[TP_BUFSIZE];
        struct  s_spcl {
                int32_t c_type; 
                time32_t c_date; 
                time32_t c_ddate; 
                int32_t c_volume;
                daddr32_t c_tapea;
                ino32_t c_inumber; 
                int32_t c_magic; 
                int32_t c_checksum;
                struct  dinode  c_dinode;
                int32_t c_count;  
                union   u_data c_data; 
                char    c_label[LBLSIZE];
                union   u_shadow c_shadow; 
                int32_t c_flags;    
                int32_t c_firstrec;        
#ifdef SUPPORTS_MTB_TAPE_FORMAT
                int32_t c_tpbsize;  
                int32_t c_spare[31]; 
#else
                int32_t c_spare[32];
#endif /* SUPPORTS_MTB_TAPE_FORMAT */
} s_spcl;
} u_spcl;

int32_t                    c_type;
time32_t                   c_date;
time32_t                   c_ddate;
int32_t                    c_volume;
daddr32_t                  c_tapea;
ino32_t                    c_inumber;
int32_t                    c_magic;
int32_t                    c_checksum;
struct dinode              c_dinode;
int32_t                    c_count;
union                      u_data c_data;
char                       c_label[LBLSIZE];
union                      u_shadow c_shadow;
int32_t                    c_flags;
int32_t                    c_firstrec;
#ifdef SUPPORTS_MTB_TAPE_FORMAT
int32_t                    c_tpbsize;
int32_t                    c_spare[31];
#else
int32_t                    c_spare[32];
#endif                       /*
     SUPPORTS_MTB_TAPE_FORMAT */

   } s_spcl;
} u_spcl;
#define spcl u_spcl.s_spcl
#define c_addr c_data.s_addrs
#define c_inos c_data.s_inos
#define c_level c_shadow.c_nonsh.c_level
#define c_filesys c_shadow.c_nonsh.c_filesys
#define c_dev c_shadow.c_nonsh.c_dev
#define c_host c_shadow.c_nonsh.c_host

#define TS_TAPE         1
#define TS_INODE        2
#define TS_ADDR         4
#define TS_BITS         3
#define TS_CLRI         6
#define TS_END          5
#define TS_EOM          7

#define DR_NEWHEADER    1
#define DR_INODEINFO    2
#define DR_REDUMP       4
#define DR_TRUEINC      8
#define DR_HASMETA      16

This header describes three formats for the ufsdump/ufsrestore interface:

• An old format, non-MTB, that supports dump sizes of less than 2 terabytes. This format is represented by NFS_MAGIC.

• A new format, MTB, that supports dump sizes of greater than 2 terabytes using a variable block size and 2 new constants: TP_BSIZE_MIN and TP_BSIZE_MAX. This format is represented by MTB_MAGIC.

• A much older format that might be found on existing backup tapes. The ufsrestore command can restore tapes of this format, but no longer generates tapes of this format. Backups in this format have the OFS_MAGIC magic number in their tape headers.

The constants are described as follows:

TP_BSIZE

Size of file blocks on the dump tapes for the old format. Note that TP_BSIZE must be a multiple of DEV_BSIZE This is applicable for dumps of type NFS_MAGIC or OFS_MAGIC, but is not applicable for dumps of type MTB_MAGIC.

TP_BSIZE_MIN

Minimum size of file blocks on the dump tapes for the new MTB format (MTB_MAGIC) only.

TP_BSIZE_MAX

Maximum size of file blocks on the dump tapes for the new MTB format (MTB_MAGIC) only.

NTREC

Number of TP_BSIZE blocks that are written in each tape record.

HIGHDENSITYNTREC

Number of TP_BSIZE blocks that are written in each tape record on 6250 BPI or higher density tapes.

CARTRIDGETREC

Number of TP_BSIZE blocks that are written in each tape record on cartridge tapes.

TP_NINDIR

Number of indirect pointers in a TS_INODE or TS_ADDR record. It must be a power of 2.

TP_NINOS

The maximum number of volumes on a tape.

LBLSIZE

The maximum size of a volume label.

NAMELEN

The maximum size of a host's name.

OFS_MAGIC

Magic number that is used for the very old format.

NFS_MAGIC

Magic number that is used for the non-MTB format.

MTB_MAGIC

Magic number that is used for the MTB format.

CHECKSUM

Header records checksum to this value.

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_ADDR

A subrecord of a file description. See s_addrs below.

TS_BITS

A bit map follows. This bit map has a one bit for each inode that was dumped.

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.

TS_END

End of tape record.

TS_EOM

diskette EOMindicates that the restore is compatible with old dump

The flags are described as follows:

DR_NEWHEADER

New format tape header.

DR_INFODEINFO

Header contains starting inode info.

DR_REDUMP

Dump contains recopies of active files.

DR_TRUEINC

Dump is a "true incremental".

DR_HASMETA

The metadata in this header.

DUMPOUTFMT

Name, incon, and ctime (date) for printf.

DUMPINFMT

Inverse for scanf.

The fields of the header structure are as follows:

s_addrs

An array of bytes describing the blocks of the dumped file. A byte is zero if the block associated with that byte was not present on the file system; otherwise, the byte is non-zero. If the block was not present on the file lsystem, no block was dumped; the block will be stored as a hole in the file. If there is not sufficient space in this record to describe all the blocks in a file, TS_ADDR records will be scattered through the file, each one picking up where the last left off

s_inos

The starting inodes on tape.

c_type

The type of the record.

c_date

The date of the previous dump.

c_ddate

The date of this dump.

c_volume

The current volume number of the dump.

c_tapea

The logical block of this 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.

c_count

The count of bytes in s_addrs.

u_data c_data

The union of either u_data c_data The union of either s_addrs or s_inos.

c_label

Label for this dump.

c_level

Level of this dump.

c_filesys

Name of dumped file system.

c_dev

Name of dumped service.

c_host

Name of dumped host.

c_flags

Additional information.

c_firstrec

First record on volume.

c_spare

Reserved for future uses.

c_tpbsize

Tape block size for MTB format only.

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 dump history is kept in the file /etc/dumpdates. It is an ASCII file with three fields separated by white space:

• The name of the device on which the dumped file system resides.

• The level number of the dump tape; see ufsdump(1M).

• The date of the incremental dump in the format generated by ctime(3C).

DUMPOUTFMT is the format to use when using printf(3C) to write an entry to /etc/dumpdates; DUMPINFMT is the format to use when using scanf(3C) to read an entry from /etc/dumpdates.

Attributes

See attributes(5) for a description of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Stability Level	Unstable

See Also

ufsdump(1M), ufsrestore(1M), ctime(3C), printf(3C), scanf(3C), types.h(3HEAD), attributes(5),

Name | Synopsis | Description | Attributes | See Also