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NAME
bkreg - change or display the contents of a backup register
SYNOPSIS
bkreg
-p period [-w cweek] [-t table]
bkreg
-a tag -o orig -c weeks:days|demand -d ddev -m
method|migration
[-b moptions] [-t table] [-D depend] [-P prio]
bkreg
-e tag [-o orig] [-c weeks:days|demand] [-m
method|migration] [-d ddev] [-t table] [-b moptions]
[-D depend] [-P prio]
bkreg
-r tag [-t table]
bkreg
[-A|-O|-R] [-hsv] [-t table] [-c weeks[:days]|demand]
bkreg
-C fields [-hv] [-t table] [-c weeks[:days]|demand] [-f
c]
DESCRIPTION
A backup register is a file containing descriptions of
backup operations to be performed on a UNIX system. The
default backup register is located in /etc/bkup/bkreg.tab.
Other backup registers may be created. The bkreg command
may be executed only by a user with superuser privilege.
Each entry in a backup register describes backup operations
to be performed on a given disk object (called the originat-
ing object) for some set of days and weeks during a rotation
period. There may be several register entries for an
object, but only one entry may specify backup operations for
an object on a specific day and week of the rotation period.
The entry describes the object, the backup method to be used
to archive the object, and the destination volumes to be
used to store the archive. Each entry has a unique tag that
identifies it. Tags must conform to file naming conven-
tions.
Rotation Period
Backups are performed in a rotation period specified in
weeks. When the end of a rotation period is reached, a new
period begins. Rotation periods begin on Sundays. The
default rotation period is one week.
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Originating Objects
An originating object is either a raw data partition or a
filesystem. An originating object is described by its ori-
ginating object name, its device name, and optional volume
labels. Several backup operations for different originating
objects may be active concurrently by specifying priorities
and dependencies. During a backup session, higher priority
backup operations are attempted before lower priority backup
operations. All backup operations of a given priority may
proceed concurrently unless dependencies are specified. If
one backup is declared to be dependent on others, it will
not be started until all of its antecedents have completed
successfully.
Destination Devices
Each backup archive is written to a set of storage volumes
inserted into a destination device. A destination device
can have destination device group, a destination device
name, media characteristics, and volume labels. Default
characteristics for a medium (as specified in the device
table) may be overridden (see the ``Device Management''
chapter in the System Administrator's Guide).
Backup Methods
An originating object is backed up to a destination device
archive using a method. The method determines the amount of
information backed up and the representation of that infor-
mation. Different methods may be used for a given originat-
ing object on different days of the rotation. Each method
accepts a set of options that are specific to the method.
Several default methods are provided with the Backup ser-
vice. Others methods may be added by a UNIX system site.
For descriptions of the default methods, see incfile(1M),
ffile(1M), fdisk(1M), fimage(1M), and fdp(1M). A backup
archive may be migrated to a different destination by speci-
fying migration as the backup method. The device name of
the originating object for a migration must have been the
destination device for a previously successful backup opera-
tion. This form of backup does not re-archive the originat-
ing object. It copies an archive from one destination to
another, updating the backup service's databases so that
restores can still be done automatically.
Register Validations
There are items in a single backup register entry and items
across register entries that must be consistent for the
backup service to conduct a backup session correctly. Some
of these consistencies are checked at the time the backup
register is created or changed. Others can be checked only
at the time the backup register is used by backup(1M). See
backup(1M) for a complete list of validations.
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Modes
The bkreg command has two modes: changing the contents of a
backup register and displaying the contents of a backup
register.
Changing Contents
bkreg -p
changes the rotation period for a backup register.
The default rotation period is one week.
bkreg -a
adds an entry to a backup register. This option
requires other options to be specified. These are
listed below under Options.
bkreg -e
edits an existing entry in a backup register.
bkreg -r
removes an existing entry from a backup register.
Displaying Contents
bkreg -C
produces a customized display of the contents of a
backup register.
bkreg [-A|-R|-O]
produces a summary display of the contents of a
backup register.
Options
-a Adds a new entry to the default backup register.
Options required with -a are: tag, originating device,
weeks:days, destination device, and method. If other
options are not specified, the following defaults are
used: the default backup register is used, no method
options are specified, the priority is 0, and no depen-
dencies exist between entries.
-b moptions
Each backup method supports a specific set of options
that modify its behavior. moptions is specified as a
list of options that are blank-separated and enclosed
in quotes. The argument string provided here is passed
to the method exactly as entered, without modification.
For lists of valid options, see ``The Backup Service''
chapter in the System Administrator's Guide and the
following entries in this book: fdisk(1M), fdp(1M),
ffile(1M), fimage(1M), and incfile(1M).
-c weeks:days|demand
Sets the week(s) and day(s) of the rotation period
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during which a backup entry should be performed or for
which a display should be generated.
weeks is a set of numbers including 1 and 52. The
value of weeks cannot be greater than the value of
-pperiod. weeks is specified as a combination of lists
or ranges (either comma-separated or blank-separated
and enclosed in quotes). An example set of weeks is
``1 3-10,13''
indicating the first week, each of the third through
tenth weeks, and the thirteenth week of the rotation
period.
days is either a set of numbers between 0 (Sunday) and
6 (Saturday), or a set of abbreviations between s (Sun-
day) and sa (Saturday). In addition, days are speci-
fied as a combination of lists or ranges (either
comma-separated or blank-separated and enclosed in
quotes).
demand indicates that an entry is used only when expli-
citly requested by
backup -c demand
-d ddev
Specifies ddev as the destination device for the backup
operation. ddev is of the form:
[dgroup][:[ddevice][:dchar][:dmname]]
where either dgroup or ddevice must be specified and
dchar and dmname are optional. (Both dgroup and ddev
may be specified together.) Colons delineate field
boundaries and must be included as indicated above.
dgroup is the device group for the destination device.
[See devgroup.tab(4).] If omitted, ddevice must be
specified.
ddevice is the device name of a specific destination
device. [See device.tab(4).] If omitted, dgroup must
be specified and any available device in dgroup may be
used.
dchar describes media characteristics. If specified,
they override the default characteristics for the dev-
ice and group. dchar is of the form:
keyword=value
where keyword is a valid device characteristic keyword
(as it appears in the device table.) dchar entries may
be separated by commas or blanks. If separated by
blanks, the entire string of arguments to ddev must be
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enclosed in quotes.
dlabels is a list of volume names of the destination
volumes. The list of dlabels must be either comma-
separated or blank-separated. If blank-separated, the
entire ddev argument must be surrounded by quotes.
Each dlabel corresponds to a volumename specified on
the labelit command. If dlabels is omitted, backup and
restore do not validate the volume labels on this
entry.
-e Edits an existing entry. If any of the options -b, -c,
-d, -m, -o, -D, or -P are present, they replace the
current settings for the specified entry in the regis-
ter.
-f c Overrides the default output field separator. c is the
character that will appear as the field separator on
the display output. The default output field separator
is colon (:).
-h Suppresses headers when generating displays.
-m method|migration
Performs the backup using the specified method. Default
methods are: incfile, ffile, fdisk, fimage, and fdp.
If the method to be used is not a default method, it
must appear as the executable file in the standard
method directory /etc/bkup/method. migration indicates
that the value of orig (following the -o option)
matches the value of ddev during a prior backup opera-
tion. The originating object is not rearchived; it is
simply copied to the location specified by ddev (fol-
lowing the -d option). The backup history (if any) and
tables of contents (if any) are updated to reflect the
changed destination for the original archive.
-o orig
Specifies orig as the originating object for the backup
operation. orig is specified in the following format:
oname:odevice[:omname]
where oname is the name of an originating object. For
file system partitions, it is the nodename on which the
file system is usually mounted, mount. For data parti-
tions, it is any valid path name. This value is pro-
vided to the backup method and validated by backup.
The default data partition backup methods, fdp and
fdisk, do not validate this name.
odevice is the device name for the originating object.
In all cases, it is a raw disk partition device name.
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For AT&T 3B2 computers, this name is specified in the
following format: /dev/rdsk/c?d?s?.
olabel is the volume label for the originating object.
For file system partitions, it corresponds to the
volumename displayed by the labelit command. A data
partition may have an associated volume name that
appears nowhere except on the outside of the volume
(where it is taped); getvol may be used to have an
operator validate the name.
On AT&T 3B2 computers, the special data partition
/dev/rdsk/c?d?s6 names an entire disk and is used when
disk formatting or repartitioning is done to reference
the disk's volume table of contents (VTOC). [See
fmthard(1M) and prtvtoc(1M).] backup validates this
special full disk partition with the disk volume name
specified when the disk was partitioned. [See
fmthard(1M).] If the disk volume name is omitted,
backup does not validate the volume labels for this
originating object.
-p period
Sets the rotation period (in weeks) for the backup
register to period. The minimum value is 1; the max-
imum value is 52. By default the current week of the
rotation is set to 1.
-r Removes the specified entries from the register.
-s Suppresses wrap-around behavior when generating
displays. Normal behavior is to wrap long values
within each field.
-t table
Uses table instead of the default register, bkreg.tab.
-v Generates displays using (vertical) columns instead of
(horizontal) rows. This allows more information to be
displayed without encountering problems displaying long
lines.
-w cweek
Overrides the default behavior by setting the current
week of the rotation period to cweek. cweek is an
integer between 1 and the value of period. The default
is 1.
-A Displays a report describing all fields in the regis-
ter. The display produced by this option is best
suited as input to a filter, since in horizontal mode
it produces extremely long lines.
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-C fields
Generates a display of the contents of a backup regis-
ter, limiting the display to the specified fields. The
output is a set of lines, one per register entry. Each
line consists of the desired fields, separated by a
field separator character. fields is a list of field
names (either comma-separated or blank-separated and
enclosed in quotes) for the fields desired. The valid
field names are period, cweek, tag, oname, odevice,
olabel, weeks, days, method, moptions, prio, depend,
dgroup, ddevice, dchar, and dlabel.
-D depend
Specifies a set of backup operations that must be com-
pleted successfully before this operation may begin.
depend is a list of tag(s) (either comma-separated or
blank-separated and enclosed in quotes) naming the
antecedent backup operations.
-f c Overrides the default output field separator. c is the
character that will appear as the field separator on
the display output. The default output field separator
is colon (":").
-O Displays a summary of all originating objects with
entries in the register.
-P prio
Sets a priority of prio for this backup operation. The
default priority is 0; the highest priority is 100.
All backup operations with the same priority may run
simultaneously, unless the priority is 0. All backups
with priority 0 run sequentially in an unspecified
order.
-R Displays a summary of all destination devices with
entries in the register.
DIAGNOSTICS
The exit codes for bkreg are the following:
0 = the task completed successfully
1 = one or more parameters to bkreg are invalid
2 = an error has occurred, causing bkreg to fail to
complete all portions of its task
Errors are reported on standard error if any of the follow-
ing occurs:
1. The tag specified in bkreg -e or bkreg -r does not
exist in the backup register.
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2. The tag specified in bkreg -a already exists in the
register.
EXAMPLES
Example 1:
bkreg -p 15 -w 3
establishes a 15-week rotation period in the default backup
register and sets the current week to the 3rd week of the
rotation period. Example 2:
bkreg -a acct5 -t wklybu.tab \
-o /usr:/dev/rdsk/c1d0s2:usr -c "2 4-6 8 10:0,2,5" \
-m incfile -b -txE \
-d diskette:capacity=1404:acctwkly1,acctwkly2,acctwkly3 \
adds an entry named acct5 to the backup register named
wklybu.tab. If wklybu.tab does not already exist, it will
be created. The originating object to be backed up is the
/usr file system on the /dev/rdsk/c1d0s2 device which is
known as usr. The backup will be performed each Sunday,
Tuesday, and Friday of the second, fourth through sixth,
eighth, and tenth weeks of the rotation period using the
incfile (incremental file) method. The method options
specify that a table of contents will be created on addi-
tional media instead of in the backup history log, the
exception list is to be ignored, and an estimate of the
number of volumes for the archive is to be provided before
performing the backup. The backup will be done to the next
available diskette device using the three diskette volumes
acctwkly1, acctwkly2, and acctwkly3. These volumes have a
capacity of 1404 blocks each.
Example 3:
bkreg -e services2 -t wklybu.tab \
-o /back:/dev/rdsk/c1d0s8:back -m migration \
-c demand -d ctape:/dev/rdsk/c4d0s3 \
changes the specifications for the backup operation named
services2 on the backup table wklybu.tab so that whenever
the command backup -c demand is executed, the backup that
was performed to the destination device
back:dev/rdsk/c1d0s2:back will be migrated from that device
(now serving as the originating device) to a cartridge tape.
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Example 4:
bkreg -e pubsfri -P 10 -D develfri,marketfri,acctfri
changes the priority level for the backup operation named
pubsfri to 10 and makes this backup operation dependent on
the three backup operations develfri, marketfri, and
acctfri. The pubsfri operation will be done only after all
backup operations with priorities greater than 10 have begun
and after the develfri, marketfri, and acctfri operations
have been completed successfully.
Example 5:
bkreg -c 1-8:0-6
provides the default display of the contents of the default
backup register, for all weekdays for the first through
eighth weeks of the rotation period. The information in the
register will be displayed in the following format:
Rotation Period = 10 Current Week = 4
Originating Device: / /dev/root
Tag Weeks Days Method Options Pri Dgroup
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
rootdai 1-8 1-6 incfile diskette
rootsp 1-8 0 ffile -bxt 20 ctape
Originating Device: /usr /dev/dsk/c1d0s2
Tag Weeks Days Method Options Pri Dgroup
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
usrdai 1-8 1-5 incfile diskette
usrsp 1-8 0 ffile -bxt 15 ctape
FILES
/etc/bkup/method/*
/etc/bkup/bkreg.tab
describes the backup policy established by
the administrator
/etc/dgroup.tab
lists logical groupings of devices as deter-
mined by the administrator
/etc/device.tab
describes specific devices and their attri-
butes
SEE ALSO
backup(1M), fdisk(1M), fdp(1M), incfile(1M), ffile(1M),
fimage(1M), fmthard(1M), getvol(1M), labelit(1M), mkfs(1M),
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mount(1M), prtvtoc(1M), restore(1M)
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