4 \chapter{Storage Media Output Format}
6 \index{Format!Storage Media Output}
7 \index{Storage Media Output Format}
8 \addcontentsline{toc}{section}{Storage Media Output Format}
12 \addcontentsline{toc}{subsection}{General}
14 This document describes the media format written by the Storage daemon. The
15 Storage daemon reads and writes in units of blocks. Blocks contain records.
16 Each block has a block header followed by records, and each record has a
17 record header followed by record data.
19 This chapter is intended to be a technical discussion of the Media Format and
20 as such is not targeted at end users but rather at developers and system
21 administrators that want or need to know more of the working details of {\bf
26 \addcontentsline{toc}{subsection}{Definitions}
32 A block represents the primitive unit of information that the Storage daemon
33 reads and writes to a physical device. Normally, for a tape device, it will
34 be the same as a tape block. The Storage daemon always reads and writes
35 blocks. A block consists of block header information followed by records.
36 Clients of the Storage daemon (the File daemon) normally never see blocks.
37 However, some of the Storage tools (bls, bscan, bextract, ...) may be use
38 block header information. In older Bacula tape versions, a block could
39 contain records (see record definition below) from multiple jobs. However,
40 all blocks currently written by Bacula are block level BB02, and a given
41 block contains records for only a single job. Different jobs simply have
42 their own private blocks that are intermingled with the other blocks from
43 other jobs on the Volume (previously the records were intermingled within
44 the blocks). Having only records from a single job in any give block
45 permitted moving the VolumeSessionId and VolumeSessionTime (see below) from
46 each record heading to the Block header. This has two advantages: 1. a block
47 can be quickly rejected based on the contents of the header without reading
48 all the records. 2. because there is on the average more than one record per
49 block, less data is written to the Volume for each job.
53 A record consists of a Record Header, which is managed by the Storage daemon
54 and Record Data, which is the data received from the Client. A record is the
55 primitive unit of information sent to and from the Storage daemon by the
56 Client (File daemon) programs. The details are described below.
60 A number assigned by the Director daemon for a particular job. This number
61 will be unique for that particular Director (Catalog). The daemons use this
62 number to keep track of individual jobs. Within the Storage daemon, the JobId
63 may not be unique if several Directors are accessing the Storage daemon
68 A Session is a concept used in the Storage daemon corresponds one to one to a
69 Job with the exception that each session is uniquely identified within the
70 Storage daemon by a unique SessionId/SessionTime pair (see below).
74 A unique number assigned by the Storage daemon to a particular session (Job)
75 it is having with a File daemon. This number by itself is not unique to the
76 given Volume, but with the VolSessionTime, it is unique.
78 \item [VolSessionTime]
79 \index{VolSessionTime}
80 A unique number assigned by the Storage daemon to a particular Storage daemon
81 execution. It is actually the Unix time\_t value of when the Storage daemon
82 began execution cast to a 32 bit unsigned integer. The combination of the
83 {\bf VolSessionId} and the {\bf VolSessionTime} for a given Storage daemon is
84 guaranteed to be unique for each Job (or session).
88 A sequential number beginning at one assigned by the File daemon to the files
89 within a job that are sent to the Storage daemon for backup. The Storage
90 daemon ensures that this number is greater than zero and sequential. Note,
91 the Storage daemon uses negative FileIndexes to flag Session Start and End
92 Labels as well as End of Volume Labels. Thus, the combination of
93 VolSessionId, VolSessionTime, and FileIndex uniquely identifies the records
94 for a single file written to a Volume.
98 While writing the information for any particular file to the Volume, there
99 can be any number of distinct pieces of information about that file, e.g. the
100 attributes, the file data, ... The Stream indicates what piece of data it
101 is, and it is an arbitrary number assigned by the File daemon to the parts
102 (Unix attributes, Win32 attributes, data, compressed data,\ ...) of a file
103 that are sent to the Storage daemon. The Storage daemon has no knowledge of
104 the details of a Stream; it simply represents a numbered stream of bytes. The
105 data for a given stream may be passed to the Storage daemon in single record,
106 or in multiple records.
110 A block header consists of a block identification (``BB02''), a block length
111 in bytes (typically 64,512) a checksum, and sequential block number. Each
112 block starts with a Block Header and is followed by Records. Current block
113 headers also contain the VolSessionId and VolSessionTime for the records
114 written to that block.
116 \item [Record Header]
117 \index{Record Header}
118 A record header contains the Volume Session Id, the Volume Session Time, the
119 FileIndex, the Stream, and the size of the data record which follows. The
120 Record Header is always immediately followed by a Data Record if the size
121 given in the Header is greater than zero. Note, for Block headers of level
122 BB02 (version 1.27 and later), the Record header as written to tape does not
123 contain the Volume Session Id and the Volume Session Time as these two
124 fields are stored in the BB02 Block header. The in-memory record header does
125 have those fields for convenience.
129 A data record consists of a binary stream of bytes and is always preceded by
130 a Record Header. The details of the meaning of the binary stream of bytes are
131 unknown to the Storage daemon, but the Client programs (File daemon) defines
132 and thus knows the details of each record type.
136 A label placed by the Storage daemon at the beginning of each storage volume.
137 It contains general information about the volume. It is written in Record
138 format. The Storage daemon manages Volume Labels, and if the client wants, he
141 \item [Begin Session Label]
142 \index{Begin Session Label}
143 The Begin Session Label is a special record placed by the Storage daemon on
144 the storage medium as the first record of an append session job with a File
145 daemon. This record is useful for finding the beginning of a particular
146 session (Job), since no records with the same VolSessionId and VolSessionTime
147 will precede this record. This record is not normally visible outside of the
148 Storage daemon. The Begin Session Label is similar to the Volume Label except
149 that it contains additional information pertaining to the Session.
151 \item [End Session Label]
152 \index{End Session Label}
153 The End Session Label is a special record placed by the Storage daemon on the
154 storage medium as the last record of an append session job with a File
155 daemon. The End Session Record is distinguished by a FileIndex with a value
156 of minus two (-2). This record is useful for detecting the end of a
157 particular session since no records with the same VolSessionId and
158 VolSessionTime will follow this record. This record is not normally visible
159 outside of the Storage daemon. The End Session Label is similar to the Volume
160 Label except that it contains additional information pertaining to the
164 \section{Storage Daemon File Output Format}
165 \index{Format!Storage Daemon File Output}
166 \index{Storage Daemon File Output Format}
167 \addcontentsline{toc}{subsection}{Storage Daemon File Output Format}
169 The file storage and tape storage formats are identical except that tape
170 records are by default blocked into blocks of 64,512 bytes, except for the
171 last block, which is the actual number of bytes written rounded up to a
172 multiple of 1024 whereas the last record of file storage is not rounded up.
173 The default block size of 64,512 bytes may be overridden by the user (some
174 older tape drives only support block sizes of 32K). Each Session written to
175 tape is terminated with an End of File mark (this will be removed later).
176 Sessions written to file are simply appended to the end of the file.
178 \section{Overall Format}
179 \index{Format!Overall}
180 \index{Overall Format}
181 \addcontentsline{toc}{subsection}{Overall Format}
183 A Bacula output file consists of Blocks of data. Each block contains a block
184 header followed by records. Each record consists of a record header followed
185 by the record data. The first record on a tape will always be the Volume Label
188 No Record Header will be split across Bacula blocks. However, Record Data may
189 be split across any number of Bacula blocks. Obviously this will not be the
190 case for the Volume Label which will always be smaller than the Bacula Block
193 To simplify reading tapes, the Start of Session (SOS) and End of Session (EOS)
194 records are never split across blocks. If this is about to happen, Bacula will
195 write a short block before writing the session record (actually, the SOS
196 record should always be the first record in a block, excepting perhaps the
199 Due to hardware limitations, the last block written to the tape may not be
200 fully written. If your drive permits backspace record, Bacula will backup over
201 the last record written on the tape, re-read it and verify that it was
204 When a new tape is mounted Bacula will write the full contents of the
205 partially written block to the new tape ensuring that there is no loss of
206 data. When reading a tape, Bacula will discard any block that is not totally
207 written, thus ensuring that there is no duplication of data. In addition,
208 since Bacula blocks are sequentially numbered within a Job, it is easy to
209 ensure that no block is missing or duplicated.
211 \section{Serialization}
212 \index{Serialization}
213 \addcontentsline{toc}{subsection}{Serialization}
215 All Block Headers, Record Headers, and Label Records are written using
216 Bacula's serialization routines. These routines guarantee that the data is
217 written to the output volume in a machine independent format.
219 \section{Block Header}
222 \addcontentsline{toc}{subsection}{Block Header}
224 The format of the Block Header (version 1.27 and later) is:
228 uint32_t CheckSum; /* Block check sum */
229 uint32_t BlockSize; /* Block byte size including the header */
230 uint32_t BlockNumber; /* Block number */
231 char ID[4] = "BB02"; /* Identification and block level */
232 uint32_t VolSessionId; /* Session Id for Job */
233 uint32_t VolSessionTime; /* Session Time for Job */
237 The Block header is a fixed length and fixed format and is followed by Record
238 Headers and Record Data. The CheckSum field is a 32 bit checksum of the block
239 data and the block header but not including the CheckSum field. The Block
240 Header is always immediately followed by a Record Header. If the tape is
241 damaged, a Bacula utility will be able to recover as much information as
242 possible from the tape by recovering blocks which are valid. The Block header
243 is written using the Bacula serialization routines and thus is guaranteed to
244 be in machine independent format. See below for version 2 of the block header.
247 \section{Record Header}
248 \index{Header!Record}
249 \index{Record Header}
250 \addcontentsline{toc}{subsection}{Record Header}
252 Each binary data record is preceded by a Record Header. The Record Header is
253 fixed length and fixed format, whereas the binary data record is of variable
254 length. The Record Header is written using the Bacula serialization routines
255 and thus is guaranteed to be in machine independent format.
257 The format of the Record Header (version 1.27 or later) is:
261 int32_t FileIndex; /* File index supplied by File daemon */
262 int32_t Stream; /* Stream number supplied by File daemon */
263 uint32_t DataSize; /* size of following data record in bytes */
267 This record is followed by the binary Stream data of DataSize bytes, followed
268 by another Record Header record and the binary stream data. For the definitive
269 definition of this record, see record.h in the src/stored directory.
271 Additional notes on the above:
275 \item [The {\bf VolSessionId} ]
277 is a unique sequential number that is assigned by the Storage Daemon to a
278 particular Job. This number is sequential since the start of execution of the
281 \item [The {\bf VolSessionTime} ]
282 \index{VolSessionTime}
283 is the time/date that the current execution of the Storage Daemon started. It
284 assures that the combination of VolSessionId and VolSessionTime is unique for
285 every jobs written to the tape, even if there was a machine crash between two
288 \item [The {\bf FileIndex} ]
290 is a sequential file number within a job. The Storage daemon requires this
291 index to be greater than zero and sequential. Note, however, that the File
292 daemon may send multiple Streams for the same FileIndex. In addition, the
293 Storage daemon uses negative FileIndices to hold the Begin Session Label, the
294 End Session Label, and the End of Volume Label.
296 \item [The {\bf Stream} ]
298 is defined by the File daemon and is used to identify separate parts of the
299 data saved for each file (Unix attributes, Win32 attributes, file data,
300 compressed file data, sparse file data, ...). The Storage Daemon has no idea
301 of what a Stream is or what it contains except that the Stream is required to
302 be a positive integer. Negative Stream numbers are used internally by the
303 Storage daemon to indicate that the record is a continuation of the previous
304 record (the previous record would not entirely fit in the block).
306 For Start Session and End Session Labels (where the FileIndex is negative),
307 the Storage daemon uses the Stream field to contain the JobId. The current
308 stream definitions are:
312 #define STREAM_UNIX_ATTRIBUTES 1 /* Generic Unix attributes */
313 #define STREAM_FILE_DATA 2 /* Standard uncompressed data */
314 #define STREAM_MD5_SIGNATURE 3 /* MD5 signature for the file */
315 #define STREAM_GZIP_DATA 4 /* GZip compressed file data */
316 /* Extended Unix attributes with Win32 Extended data. Deprecated. */
317 #define STREAM_UNIX_ATTRIBUTES_EX 5 /* Extended Unix attr for Win32 EX */
318 #define STREAM_SPARSE_DATA 6 /* Sparse data stream */
319 #define STREAM_SPARSE_GZIP_DATA 7
320 #define STREAM_PROGRAM_NAMES 8 /* program names for program data */
321 #define STREAM_PROGRAM_DATA 9 /* Data needing program */
322 #define STREAM_SHA1_SIGNATURE 10 /* SHA1 signature for the file */
323 #define STREAM_WIN32_DATA 11 /* Win32 BackupRead data */
324 #define STREAM_WIN32_GZIP_DATA 12 /* Gzipped Win32 BackupRead data */
325 #define STREAM_MACOS_FORK_DATA 13 /* Mac resource fork */
326 #define STREAM_HFSPLUS_ATTRIBUTES 14 /* Mac OS extra attributes */
327 #define STREAM_UNIX_ATTRIBUTES_ACCESS_ACL 15 /* Standard ACL attributes on UNIX */
328 #define STREAM_UNIX_ATTRIBUTES_DEFAULT_ACL 16 /* Default ACL attributes on UNIX */
332 \item [The {\bf DataSize} ]
334 is the size in bytes of the binary data record that follows the Session
335 Record header. The Storage Daemon has no idea of the actual contents of the
336 binary data record. For standard Unix files, the data record typically
337 contains the file attributes or the file data. For a sparse file the first
338 64 bits of the file data contains the storage address for the data block.
341 The Record Header is never split across two blocks. If there is not enough
342 room in a block for the full Record Header, the block is padded to the end
343 with zeros and the Record Header begins in the next block. The data record, on
344 the other hand, may be split across multiple blocks and even multiple physical
345 volumes. When a data record is split, the second (and possibly subsequent)
346 piece of the data is preceded by a new Record Header. Thus each piece of data
347 is always immediately preceded by a Record Header. When reading a record, if
348 Bacula finds only part of the data in the first record, it will automatically
349 read the next record and concatenate the data record to form a full data
352 \section{Version BB02 Block Header}
353 \index{Version BB02 Block Header}
354 \index{Header!Version BB02 Block}
355 \addcontentsline{toc}{subsection}{Version BB02 Block Header}
357 Each session or Job has its own private block. As a consequence, the SessionId
358 and SessionTime are written once in each Block Header and not in the Record
359 Header. So, the second and current version of the Block Header BB02 is:
363 uint32_t CheckSum; /* Block check sum */
364 uint32_t BlockSize; /* Block byte size including the header */
365 uint32_t BlockNumber; /* Block number */
366 char ID[4] = "BB02"; /* Identification and block level */
367 uint32_t VolSessionId; /* Applies to all records */
368 uint32_t VolSessionTime; /* contained in this block */
372 As with the previous version, the BB02 Block header is a fixed length and
373 fixed format and is followed by Record Headers and Record Data. The CheckSum
374 field is a 32 bit CRC checksum of the block data and the block header but not
375 including the CheckSum field. The Block Header is always immediately followed
376 by a Record Header. If the tape is damaged, a Bacula utility will be able to
377 recover as much information as possible from the tape by recovering blocks
378 which are valid. The Block header is written using the Bacula serialization
379 routines and thus is guaranteed to be in machine independent format.
381 \section{Version 2 Record Header}
382 \index{Version 2 Record Header}
383 \index{Header!Version 2 Record}
384 \addcontentsline{toc}{subsection}{Version 2 Record Header}
386 Version 2 Record Header is written to the medium when using Version BB02 Block
387 Headers. The memory representation of the record is identical to the old BB01
388 Record Header, but on the storage medium, the first two fields, namely
389 VolSessionId and VolSessionTime are not written. The Block Header is filled
390 with these values when the First user record is written (i.e. non label
391 record) so that when the block is written, it will have the current and unique
392 VolSessionId and VolSessionTime. On reading each record from the Block, the
393 VolSessionId and VolSessionTime is filled in the Record Header from the Block
396 \section{Volume Label Format}
397 \index{Volume Label Format}
398 \index{Format!Volume Label}
399 \addcontentsline{toc}{subsection}{Volume Label Format}
401 Tape volume labels are created by the Storage daemon in response to a {\bf
402 label} command given to the Console program, or alternatively by the {\bf
403 btape} program. created. Each volume is labeled with the following information
404 using the Bacula serialization routines, which guarantee machine byte order
407 For Bacula versions 1.27 and later, the Volume Label Format is:
411 char Id[32]; /* Bacula 1.0 Immortal\n */
412 uint32_t VerNum; /* Label version number */
413 /* VerNum 11 and greater Bacula 1.27 and later */
414 btime_t label_btime; /* Time/date tape labeled */
415 btime_t write_btime; /* Time/date tape first written */
416 /* The following are 0 in VerNum 11 and greater */
417 float64_t write_date; /* Date this label written */
418 float64_t write_time; /* Time this label written */
419 char VolName[128]; /* Volume name */
420 char PrevVolName[128]; /* Previous Volume Name */
421 char PoolName[128]; /* Pool name */
422 char PoolType[128]; /* Pool type */
423 char MediaType[128]; /* Type of this media */
424 char HostName[128]; /* Host name of writing computer */
425 char LabelProg[32]; /* Label program name */
426 char ProgVersion[32]; /* Program version */
427 char ProgDate[32]; /* Program build date/time */
431 Note, the LabelType (Volume Label, Volume PreLabel, Session Start Label, ...)
432 is stored in the record FileIndex field of the Record Header and does not
433 appear in the data part of the record.
435 \section{Session Label}
436 \index{Label!Session}
437 \index{Session Label}
438 \addcontentsline{toc}{subsection}{Session Label}
440 The Session Label is written at the beginning and end of each session as well
441 as the last record on the physical medium. It has the following binary format:
446 char Id[32]; /* Bacula Immortal ... */
447 uint32_t VerNum; /* Label version number */
448 uint32_t JobId; /* Job id */
449 uint32_t VolumeIndex; /* sequence no of vol */
450 /* Prior to VerNum 11 */
451 float64_t write_date; /* Date this label written */
452 /* VerNum 11 and greater */
453 btime_t write_btime; /* time/date record written */
454 /* The following is zero VerNum 11 and greater */
455 float64_t write_time; /* Time this label written */
456 char PoolName[128]; /* Pool name */
457 char PoolType[128]; /* Pool type */
458 char JobName[128]; /* base Job name */
459 char ClientName[128];
460 /* Added in VerNum 10 */
461 char Job[128]; /* Unique Job name */
462 char FileSetName[128]; /* FileSet name */
468 In addition, the EOS label contains:
472 /* The remainder are part of EOS label only */
475 uint32_t start_block;
483 In addition, for VerNum greater than 10, the EOS label contains (in addition
488 uint32_t JobStatus /* Job termination code */
492 : Note, the LabelType (Volume Label, Volume PreLabel, Session Start Label,
493 ...) is stored in the record FileIndex field and does not appear in the data
494 part of the record. Also, the Stream field of the Record Header contains the
495 JobId. This permits quick filtering without actually reading all the session
498 \section{Overall Storage Format}
499 \index{Format!Overall Storage}
500 \index{Overall Storage Format}
501 \addcontentsline{toc}{subsection}{Overall Storage Format}
505 Current Bacula Tape Format
507 Version BB02 added 28 September 2002
508 Version BB01 is the old deprecated format.
509 A Bacula tape is composed of tape Blocks. Each block
510 has a Block header followed by the block data. Block
511 Data consists of Records. Records consist of Record
512 Headers followed by Record Data.
513 :=======================================================:
515 | Block Header (24 bytes) |
517 |-------------------------------------------------------|
519 | Record Header (12 bytes) |
521 |-------------------------------------------------------|
525 |-------------------------------------------------------|
527 | Record Header (12 bytes) |
529 |-------------------------------------------------------|
532 Block Header: the first item in each block. The format is
534 Partial Data block: occurs if the data from a previous
535 block spills over to this block (the normal case except
536 for the first block on a tape). However, this partial
537 data block is always preceded by a record header.
538 Record Header: identifies the Volume Session, the Stream
539 and the following Record Data size. See below for format.
540 Record data: arbitrary binary data.
541 Block Header Format BB02
542 :=======================================================:
543 | CheckSum (uint32_t) |
544 |-------------------------------------------------------|
545 | BlockSize (uint32_t) |
546 |-------------------------------------------------------|
547 | BlockNumber (uint32_t) |
548 |-------------------------------------------------------|
549 | "BB02" (char [4]) |
550 |-------------------------------------------------------|
551 | VolSessionId (uint32_t) |
552 |-------------------------------------------------------|
553 | VolSessionTime (uint32_t) |
554 :=======================================================:
555 BBO2: Serves to identify the block as a
556 Bacula block and also servers as a block format identifier
557 should we ever need to change the format.
558 BlockSize: is the size in bytes of the block. When reading
559 back a block, if the BlockSize does not agree with the
560 actual size read, Bacula discards the block.
561 CheckSum: a checksum for the Block.
562 BlockNumber: is the sequential block number on the tape.
563 VolSessionId: a unique sequential number that is assigned
564 by the Storage Daemon to a particular Job.
565 This number is sequential since the start
566 of execution of the daemon.
567 VolSessionTime: the time/date that the current execution
568 of the Storage Daemon started. It assures
569 that the combination of VolSessionId and
570 VolSessionTime is unique for all jobs
571 written to the tape, even if there was a
572 machine crash between two writes.
573 Record Header Format BB02
574 :=======================================================:
575 | FileIndex (int32_t) |
576 |-------------------------------------------------------|
578 |-------------------------------------------------------|
579 | DataSize (uint32_t) |
580 :=======================================================:
581 FileIndex: a sequential file number within a job. The
582 Storage daemon enforces this index to be
583 greater than zero and sequential. Note,
584 however, that the File daemon may send
585 multiple Streams for the same FileIndex.
586 The Storage Daemon uses negative FileIndices
587 to identify Session Start and End labels
588 as well as the End of Volume labels.
589 Stream: defined by the File daemon and is intended to be
590 used to identify separate parts of the data
591 saved for each file (attributes, file data,
592 ...). The Storage Daemon has no idea of
593 what a Stream is or what it contains.
594 DataSize: the size in bytes of the binary data record
595 that follows the Session Record header.
596 The Storage Daemon has no idea of the
597 actual contents of the binary data record.
598 For standard Unix files, the data record
599 typically contains the file attributes or
600 the file data. For a sparse file
601 the first 64 bits of the data contains
602 the storage address for the data block.
604 :=======================================================:
606 |-------------------------------------------------------|
607 | VerNum (uint32_t) |
608 |-------------------------------------------------------|
609 | label_date (float64_t) |
610 | label_btime (btime_t VerNum 11 |
611 |-------------------------------------------------------|
612 | label_time (float64_t) |
613 | write_btime (btime_t VerNum 11 |
614 |-------------------------------------------------------|
615 | write_date (float64_t) |
616 | 0 (float64_t) VerNum 11 |
617 |-------------------------------------------------------|
618 | write_time (float64_t) |
619 | 0 (float64_t) VerNum 11 |
620 |-------------------------------------------------------|
621 | VolName (128 bytes) |
622 |-------------------------------------------------------|
623 | PrevVolName (128 bytes) |
624 |-------------------------------------------------------|
625 | PoolName (128 bytes) |
626 |-------------------------------------------------------|
627 | PoolType (128 bytes) |
628 |-------------------------------------------------------|
629 | MediaType (128 bytes) |
630 |-------------------------------------------------------|
631 | HostName (128 bytes) |
632 |-------------------------------------------------------|
633 | LabelProg (32 bytes) |
634 |-------------------------------------------------------|
635 | ProgVersion (32 bytes) |
636 |-------------------------------------------------------|
637 | ProgDate (32 bytes) |
638 |-------------------------------------------------------|
639 :=======================================================:
641 Id: 32 byte Bacula identifier "Bacula 1.0 immortal\n"
642 (old version also recognized:)
643 Id: 32 byte Bacula identifier "Bacula 0.9 mortal\n"
644 LabelType (Saved in the FileIndex of the Header record).
645 PRE_LABEL -1 Volume label on unwritten tape
646 VOL_LABEL -2 Volume label after tape written
647 EOM_LABEL -3 Label at EOM (not currently implemented)
648 SOS_LABEL -4 Start of Session label (format given below)
649 EOS_LABEL -5 End of Session label (format given below)
651 label_date: Julian day tape labeled
652 label_time: Julian time tape labeled
653 write_date: Julian date tape first used (data written)
654 write_time: Julian time tape first used (data written)
655 VolName: "Physical" Volume name
656 PrevVolName: The VolName of the previous tape (if this tape is
657 a continuation of the previous one).
660 MediaType: Media Type
661 HostName: Name of host that is first writing the tape
662 LabelProg: Name of the program that labeled the tape
663 ProgVersion: Version of the label program
664 ProgDate: Date Label program built
666 :=======================================================:
668 |-------------------------------------------------------|
669 | VerNum (uint32_t) |
670 |-------------------------------------------------------|
672 |-------------------------------------------------------|
673 | write_btime (btime_t) VerNum 11 |
674 |-------------------------------------------------------|
675 | 0 (float64_t) VerNum 11 |
676 |-------------------------------------------------------|
677 | PoolName (128 bytes) |
678 |-------------------------------------------------------|
679 | PoolType (128 bytes) |
680 |-------------------------------------------------------|
681 | JobName (128 bytes) |
682 |-------------------------------------------------------|
683 | ClientName (128 bytes) |
684 |-------------------------------------------------------|
686 |-------------------------------------------------------|
687 | FileSetName (128 bytes) |
688 |-------------------------------------------------------|
689 | JobType (uint32_t) |
690 |-------------------------------------------------------|
691 | JobLevel (uint32_t) |
692 |-------------------------------------------------------|
693 | FileSetMD5 (50 bytes) VerNum 11 |
694 |-------------------------------------------------------|
695 Additional fields in End Of Session Label
696 |-------------------------------------------------------|
697 | JobFiles (uint32_t) |
698 |-------------------------------------------------------|
699 | JobBytes (uint32_t) |
700 |-------------------------------------------------------|
701 | start_block (uint32_t) |
702 |-------------------------------------------------------|
703 | end_block (uint32_t) |
704 |-------------------------------------------------------|
705 | start_file (uint32_t) |
706 |-------------------------------------------------------|
707 | end_file (uint32_t) |
708 |-------------------------------------------------------|
709 | JobErrors (uint32_t) |
710 |-------------------------------------------------------|
711 | JobStatus (uint32_t) VerNum 11 |
712 :=======================================================:
713 * => fields deprecated
714 Id: 32 byte Bacula Identifier "Bacula 1.0 immortal\n"
715 LabelType (in FileIndex field of Header):
716 EOM_LABEL -3 Label at EOM
717 SOS_LABEL -4 Start of Session label
718 EOS_LABEL -5 End of Session label
721 write_btime: Bacula time/date this tape record written
722 write_date: Julian date tape this record written - deprecated
723 write_time: Julian time tape this record written - deprecated.
726 MediaType: Media Type
727 ClientName: Name of File daemon or Client writing this session
728 Not used for EOM_LABEL.
732 \section{Unix File Attributes}
733 \index{Unix File Attributes}
734 \index{Attributes!Unix File}
735 \addcontentsline{toc}{subsection}{Unix File Attributes}
737 The Unix File Attributes packet consists of the following:
739 \lt{}File-Index\gt{} \lt{}Type\gt{}
740 \lt{}Filename\gt{}@\lt{}File-Attributes\gt{}@\lt{}Link\gt{}
741 @\lt{}Extended-Attributes@\gt{} where
746 represents a byte containing a binary zero.
750 is the sequential file index starting from one assigned by the File daemon.
754 is one of the following:
758 #define FT_LNKSAVED 1 /* hard link to file already saved */
759 #define FT_REGE 2 /* Regular file but empty */
760 #define FT_REG 3 /* Regular file */
761 #define FT_LNK 4 /* Soft Link */
762 #define FT_DIR 5 /* Directory */
763 #define FT_SPEC 6 /* Special file -- chr, blk, fifo, sock */
764 #define FT_NOACCESS 7 /* Not able to access */
765 #define FT_NOFOLLOW 8 /* Could not follow link */
766 #define FT_NOSTAT 9 /* Could not stat file */
767 #define FT_NOCHG 10 /* Incremental option, file not changed */
768 #define FT_DIRNOCHG 11 /* Incremental option, directory not changed */
769 #define FT_ISARCH 12 /* Trying to save archive file */
770 #define FT_NORECURSE 13 /* No recursion into directory */
771 #define FT_NOFSCHG 14 /* Different file system, prohibited */
772 #define FT_NOOPEN 15 /* Could not open directory */
773 #define FT_RAW 16 /* Raw block device */
774 #define FT_FIFO 17 /* Raw fifo device */
780 is the fully qualified filename.
782 \item [File-Attributes]
783 \index{File-Attributes}
784 consists of the 13 fields of the stat() buffer in ASCII base64 format
785 separated by spaces. These fields and their meanings are shown below. This
786 stat() packet is in Unix format, and MUST be provided (constructed) for ALL
791 when the FT code is FT\_LNK or FT\_LNKSAVED, the item in question is a Unix
792 link, and this field contains the fully qualified link name. When the FT code
793 is not FT\_LNK or FT\_LNKSAVED, this field is null.
795 \item [Extended-Attributes]
796 \index{Extended-Attributes}
797 The exact format of this field is operating system dependent. It contains
798 additional or extended attributes of a system dependent nature. Currently,
799 this field is used only on WIN32 systems where it contains a ASCII base64
800 representation of the WIN32\_FILE\_ATTRIBUTE\_DATA structure as defined by
801 Windows. The fields in the base64 representation of this structure are like
802 the File-Attributes separated by spaces.
805 The File-attributes consist of the following:
807 \addcontentsline{lot}{table}{File Attributes}
808 \begin{longtable}{|p{0.6in}|p{0.7in}|p{1in}|p{1in}|p{1.4in}|}
810 \multicolumn{1}{|c|}{\bf Field No. } & \multicolumn{1}{c|}{\bf Stat Name }
811 & \multicolumn{1}{c|}{\bf Unix } & \multicolumn{1}{c|}{\bf Win98/NT } &
812 \multicolumn{1}{c|}{\bf MacOS } \\
814 \multicolumn{1}{|c|}{1 } & {st\_dev } & {Device number of filesystem } &
815 {Drive number } & {vRefNum } \\
817 \multicolumn{1}{|c|}{2 } & {st\_ino } & {Inode number } & {Always 0 } &
820 \multicolumn{1}{|c|}{3 } & {st\_mode } & {File mode } & {File mode } &
821 {777 dirs/apps; 666 docs; 444 locked docs } \\
823 \multicolumn{1}{|c|}{4 } & {st\_nlink } & {Number of links to the file } &
824 {Number of link (only on NTFS) } & {Always 1 } \\
826 \multicolumn{1}{|c|}{5 } & {st\_uid } & {Owner ID } & {Always 0 } &
829 \multicolumn{1}{|c|}{6 } & {st\_gid } & {Group ID } & {Always 0 } &
832 \multicolumn{1}{|c|}{7 } & {st\_rdev } & {Device ID for special files } &
833 {Drive No. } & {Always 0 } \\
835 \multicolumn{1}{|c|}{8 } & {st\_size } & {File size in bytes } & {File
836 size in bytes } & {Data fork file size in bytes } \\
838 \multicolumn{1}{|c|}{9 } & {st\_blksize } & {Preferred block size } &
839 {Always 0 } & {Preferred block size } \\
841 \multicolumn{1}{|c|}{10 } & {st\_blocks } & {Number of blocks allocated }
842 & {Always 0 } & {Number of blocks allocated } \\
844 \multicolumn{1}{|c|}{11 } & {st\_atime } & {Last access time since epoch }
845 & {Last access time since epoch } & {Last access time -66 years } \\
847 \multicolumn{1}{|c|}{12 } & {st\_mtime } & {Last modify time since epoch }
848 & {Last modify time since epoch } & {Last access time -66 years } \\
850 \multicolumn{1}{|c|}{13 } & {st\_ctime } & {Inode change time since epoch
851 } & {File create time since epoch } & {File create time -66 years}
856 \section{Old Depreciated Tape Format}
857 \index{Old Depreciated Tape Format}
858 \index{Format!Old Depreciated Tape}
859 \addcontentsline{toc}{subsection}{Old Depreciated Tape Format}
861 The format of the Block Header (version 1.26 and earlier) is:
865 uint32_t CheckSum; /* Block check sum */
866 uint32_t BlockSize; /* Block byte size including the header */
867 uint32_t BlockNumber; /* Block number */
868 char ID[4] = "BB01"; /* Identification and block level */
872 The format of the Record Header (version 1.26 or earlier) is:
876 uint32_t VolSessionId; /* Unique ID for this session */
877 uint32_t VolSessionTime; /* Start time/date of session */
878 int32_t FileIndex; /* File index supplied by File daemon */
879 int32_t Stream; /* Stream number supplied by File daemon */
880 uint32_t DataSize; /* size of following data record in bytes */
886 Current Bacula Tape Format
888 Version BB01 is the old deprecated format.
889 A Bacula tape is composed of tape Blocks. Each block
890 has a Block header followed by the block data. Block
891 Data consists of Records. Records consist of Record
892 Headers followed by Record Data.
893 :=======================================================:
896 | (16 bytes version BB01) |
897 |-------------------------------------------------------|
900 | (20 bytes version BB01) |
901 |-------------------------------------------------------|
905 |-------------------------------------------------------|
908 | (20 bytes version BB01) |
909 |-------------------------------------------------------|
912 Block Header: the first item in each block. The format is
914 Partial Data block: occurs if the data from a previous
915 block spills over to this block (the normal case except
916 for the first block on a tape). However, this partial
917 data block is always preceded by a record header.
918 Record Header: identifies the Volume Session, the Stream
919 and the following Record Data size. See below for format.
920 Record data: arbitrary binary data.
921 Block Header Format BB01 (deprecated)
922 :=======================================================:
923 | CheckSum (uint32_t) |
924 |-------------------------------------------------------|
925 | BlockSize (uint32_t) |
926 |-------------------------------------------------------|
927 | BlockNumber (uint32_t) |
928 |-------------------------------------------------------|
929 | "BB01" (char [4]) |
930 :=======================================================:
931 BBO1: Serves to identify the block as a
932 Bacula block and also servers as a block format identifier
933 should we ever need to change the format.
934 BlockSize: is the size in bytes of the block. When reading
935 back a block, if the BlockSize does not agree with the
936 actual size read, Bacula discards the block.
937 CheckSum: a checksum for the Block.
938 BlockNumber: is the sequential block number on the tape.
939 VolSessionId: a unique sequential number that is assigned
940 by the Storage Daemon to a particular Job.
941 This number is sequential since the start
942 of execution of the daemon.
943 VolSessionTime: the time/date that the current execution
944 of the Storage Daemon started. It assures
945 that the combination of VolSessionId and
946 VolSessionTime is unique for all jobs
947 written to the tape, even if there was a
948 machine crash between two writes.
949 Record Header Format BB01 (deprecated)
950 :=======================================================:
951 | VolSessionId (uint32_t) |
952 |-------------------------------------------------------|
953 | VolSessionTime (uint32_t) |
954 |-------------------------------------------------------|
955 | FileIndex (int32_t) |
956 |-------------------------------------------------------|
958 |-------------------------------------------------------|
959 | DataSize (uint32_t) |
960 :=======================================================:
961 VolSessionId: a unique sequential number that is assigned
962 by the Storage Daemon to a particular Job.
963 This number is sequential since the start
964 of execution of the daemon.
965 VolSessionTime: the time/date that the current execution
966 of the Storage Daemon started. It assures
967 that the combination of VolSessionId and
968 VolSessionTime is unique for all jobs
969 written to the tape, even if there was a
970 machine crash between two writes.
971 FileIndex: a sequential file number within a job. The
972 Storage daemon enforces this index to be
973 greater than zero and sequential. Note,
974 however, that the File daemon may send
975 multiple Streams for the same FileIndex.
976 The Storage Daemon uses negative FileIndices
977 to identify Session Start and End labels
978 as well as the End of Volume labels.
979 Stream: defined by the File daemon and is intended to be
980 used to identify separate parts of the data
981 saved for each file (attributes, file data,
982 ...). The Storage Daemon has no idea of
983 what a Stream is or what it contains.
984 DataSize: the size in bytes of the binary data record
985 that follows the Session Record header.
986 The Storage Daemon has no idea of the
987 actual contents of the binary data record.
988 For standard Unix files, the data record
989 typically contains the file attributes or
990 the file data. For a sparse file
991 the first 64 bits of the data contains
992 the storage address for the data block.
994 :=======================================================:
996 |-------------------------------------------------------|
997 | VerNum (uint32_t) |
998 |-------------------------------------------------------|
999 | label_date (float64_t) |
1000 |-------------------------------------------------------|
1001 | label_time (float64_t) |
1002 |-------------------------------------------------------|
1003 | write_date (float64_t) |
1004 |-------------------------------------------------------|
1005 | write_time (float64_t) |
1006 |-------------------------------------------------------|
1007 | VolName (128 bytes) |
1008 |-------------------------------------------------------|
1009 | PrevVolName (128 bytes) |
1010 |-------------------------------------------------------|
1011 | PoolName (128 bytes) |
1012 |-------------------------------------------------------|
1013 | PoolType (128 bytes) |
1014 |-------------------------------------------------------|
1015 | MediaType (128 bytes) |
1016 |-------------------------------------------------------|
1017 | HostName (128 bytes) |
1018 |-------------------------------------------------------|
1019 | LabelProg (32 bytes) |
1020 |-------------------------------------------------------|
1021 | ProgVersion (32 bytes) |
1022 |-------------------------------------------------------|
1023 | ProgDate (32 bytes) |
1024 |-------------------------------------------------------|
1025 :=======================================================:
1027 Id: 32 byte Bacula identifier "Bacula 1.0 immortal\n"
1028 (old version also recognized:)
1029 Id: 32 byte Bacula identifier "Bacula 0.9 mortal\n"
1030 LabelType (Saved in the FileIndex of the Header record).
1031 PRE_LABEL -1 Volume label on unwritten tape
1032 VOL_LABEL -2 Volume label after tape written
1033 EOM_LABEL -3 Label at EOM (not currently implemented)
1034 SOS_LABEL -4 Start of Session label (format given below)
1035 EOS_LABEL -5 End of Session label (format given below)
1036 label_date: Julian day tape labeled
1037 label_time: Julian time tape labeled
1038 write_date: Julian date tape first used (data written)
1039 write_time: Julian time tape first used (data written)
1040 VolName: "Physical" Volume name
1041 PrevVolName: The VolName of the previous tape (if this tape is
1042 a continuation of the previous one).
1045 MediaType: Media Type
1046 HostName: Name of host that is first writing the tape
1047 LabelProg: Name of the program that labeled the tape
1048 ProgVersion: Version of the label program
1049 ProgDate: Date Label program built
1051 :=======================================================:
1053 |-------------------------------------------------------|
1054 | VerNum (uint32_t) |
1055 |-------------------------------------------------------|
1056 | JobId (uint32_t) |
1057 |-------------------------------------------------------|
1058 | *write_date (float64_t) VerNum 10 |
1059 |-------------------------------------------------------|
1060 | *write_time (float64_t) VerNum 10 |
1061 |-------------------------------------------------------|
1062 | PoolName (128 bytes) |
1063 |-------------------------------------------------------|
1064 | PoolType (128 bytes) |
1065 |-------------------------------------------------------|
1066 | JobName (128 bytes) |
1067 |-------------------------------------------------------|
1068 | ClientName (128 bytes) |
1069 |-------------------------------------------------------|
1071 |-------------------------------------------------------|
1072 | FileSetName (128 bytes) |
1073 |-------------------------------------------------------|
1074 | JobType (uint32_t) |
1075 |-------------------------------------------------------|
1076 | JobLevel (uint32_t) |
1077 |-------------------------------------------------------|
1078 | FileSetMD5 (50 bytes) VerNum 11 |
1079 |-------------------------------------------------------|
1080 Additional fields in End Of Session Label
1081 |-------------------------------------------------------|
1082 | JobFiles (uint32_t) |
1083 |-------------------------------------------------------|
1084 | JobBytes (uint32_t) |
1085 |-------------------------------------------------------|
1086 | start_block (uint32_t) |
1087 |-------------------------------------------------------|
1088 | end_block (uint32_t) |
1089 |-------------------------------------------------------|
1090 | start_file (uint32_t) |
1091 |-------------------------------------------------------|
1092 | end_file (uint32_t) |
1093 |-------------------------------------------------------|
1094 | JobErrors (uint32_t) |
1095 |-------------------------------------------------------|
1096 | JobStatus (uint32_t) VerNum 11 |
1097 :=======================================================:
1098 * => fields deprecated
1099 Id: 32 byte Bacula Identifier "Bacula 1.0 immortal\n"
1100 LabelType (in FileIndex field of Header):
1101 EOM_LABEL -3 Label at EOM
1102 SOS_LABEL -4 Start of Session label
1103 EOS_LABEL -5 End of Session label
1106 write_btime: Bacula time/date this tape record written
1107 write_date: Julian date tape this record written - deprecated
1108 write_time: Julian time tape this record written - deprecated.
1111 MediaType: Media Type
1112 ClientName: Name of File daemon or Client writing this session
1113 Not used for EOM_LABEL.