UFSDUMP(4) File Formats and Configurations UFSDUMP(4)


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:

o a header record

o two groups of bit map records

o a group of records describing directories

o 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:

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

o 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.

o 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:

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

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

o 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),


April 9, 2003 UFSDUMP(4)