NAME
backup_volsetrestore - Restores all volumes in a volume set
SYNOPSIS
backup volsetrestore [-name <volume set name>]
[-file <file name>] [-portoffset <TC port offset>+]
[-extension <new volume name extension>] [-n]
[-localauth] [-cell <cell name>] [-help]
backup vols [-na <volume set name>] [-f <file name>]
[-p <TC port offset>+] [-e <new volume name extension>]
[-n] [-l] [-c <cell name>] [-h]
DESCRIPTION
The backup volsetrestore command restores the complete contents of a
group of read/write volumes to the file system, by restoring data from
the last full dump and all subsequent incremental dumps of each volume.
It is most useful for recovering from loss of data on multiple
partitions, since it can restore each of a defined set of volumes to a
different site.
(If the "FILE YES" instruction appears in the
/var/lib/openafs/backup/CFG_device_name file associated with the
specified port offset, then the backup volsetrestore command restores
data from the backup data file listed for that port offset in the Tape
Coordinator’s /var/lib/openafs/backup/tapeconfig file, instead of from
tape. For the sake of clarity, the following text refers to tapes only,
but the Backup System handles backup data files in much the same way.)
If restoring one or more volumes to a single site only, it is usually
more efficient to use the backup volrestore command. If restoring all
volumes that resided on a single partition, it is usually more
efficient to use the backup diskrestore command.
Indicate the volumes to restore by providing either the -name argument
or the -file argument:
· The -name argument names a volume set. The Backup System restores
all volumes listed in the Volume Location Database (VLDB) that
match the server, partition, and volume name criteria defined in
the volume set’s volume entries, and for which dumps are available.
It restores the volumes to their current site (machine and
partition), and by default overwrites the existing volume contents.
It is not required that the volume set was previously used to back
up volumes (was used as the -volumeset option to the backup dump
command). It can be defined especially to match the volumes that
need to be restored with this command, and that is usually the
better choice. Indeed, a temporary volume set, created by including
the -temporary flag to the backup addvolset command, can be
especially useful in this context. A temporary volume set is not
added to the Backup Database and exists only during the current
interactive backup session, which is suitable if the volume set is
needed only to complete the single restore operation initialized by
this command.
The reason that a specially defined volume set is probably better
is that volume sets previously defined for use in dump operations
usually match the backup version of volumes, whereas for a restore
operation it is best to define volume entries that match the base
(read/write) name. In that case, the Backup System searches the
Backup Database for the newest dump set that includes either the
read/write or the backup version of the volume. If, in contrast, a
volume entry explicitly matches the volume’s backup or read-only
version, the Backup System restores dumps of that volume version
only.
· The -file argument names a file that lists specific volumes and the
site to which to restore each. The volume name must match the name
used in Backup Database dump records rather than in the VLDB, if
they differ, because the Backup System does not look up volumes in
the VLDB. The specified site can be different than the volume’s
current one; in that case, the Backup System removes the current
version of the volume and updates the volume’s location information
in the VLDB.
If all of the full and incremental dumps of all relevant volumes were
not written to a type of tape that a single Tape Coordinator can read,
use the -portoffset argument to list multiple port offset numbers in
the order in which the tapes are needed (first list the port offset for
the full dump, second the port offset for the level 1 incremental dump,
and so on). This implies that the full dumps of all relevant volumes
must have been written to a type of tape that the first Tape
Coordinator can read, the level 1 incremental dumps to a type of tape
the second Tape Coordinator can read, and so on. If dumps are on
multiple incompatible tape types, use the backup volrestore command to
restore individual volumes, or use this command after defining new
volume sets that group together volumes that were dumped to compatible
tape types. For further discussion, see the IBM AFS Administration
Guide.
By default, the Backup System overwrites the contents of an existing
volume with the restored data. To create a new volume to house the
restored version instead, use the -extension argument. The Backup
System derives the new volume’s name by adding the specified extension
to the read/write base name, and creates a new VLDB entry. The command
does not affect the existing volume in any way. However, if a volume
with the specified extension also already exists, the command
overwrites it.
The -n flag produces a list of the volumes to be restored if the -n
flag were not included, without actually restoring any volumes. See
OUTPUT for a detailed description of the output, and suggestions on how
to combine it most effectively with the -file and -name arguments.
The execution time for a backup volsetrestore command depends on the
number of volumes to be restored and the amount of data in them, but it
can take hours to restore a large number of volumes. One way to reduce
the time is to run multiple instances of the command simultaneously,
either using the -name argument to specify disjoint volume sets for
each command, or the -file argument to name files that list different
volumes. This is possible if there are multiple available Tape
Coordinators that can read the required tapes. Depending on how the
volumes to be restored were dumped to tape, specifying disjoint volume
sets can also reduce the number of tape changes required.
The Tape Coordinator’s default response to this command is to access
the first tape it needs by invoking the "MOUNT" instruction in the
local /var/lib/openafs/backup/CFG_device_name file, or by prompting the
backup operator to insert the tape if there is no "MOUNT" instruction.
However, if the "AUTOQUERY NO" instruction appears in the
CFG_device_name file, or if the issuer of the butc command included the
-noautoquery flag, the Tape Coordinator instead expects the tape to be
in the device already. If it is not, or is the wrong tape, the Tape
Coordinator invokes the "MOUNT" instruction or prompts the operator. It
also invokes the "MOUNT" instruction or prompts for any additional
tapes needed to complete the restore operation; the backup operator
must arrange to provide them.
OPTIONS
-name <volume set name>
Names a volume set to restore. The Backup System restores all of
the volumes listed in the VLDB that match the volume set’s volume
entries. Provide this argument or the -file argument, but not both.
-file <file name>
Specifies the full pathname of a file that lists one or more
volumes and the site (file server machine and partition) to which
to restore each. Use either this argument or the -name argument,
but not both.
Each volume’s entry must appear on its own (unbroken) line in the
file, and have the following format:
<machine> <partition> <volume> [<comments> ...]
where
<machine>
Names the file server machine to which to restore the volume.
<partition>
Names the partition to which to restore the volume.
<volume>
Names the volume to restore. It is generally best to specify
the base (read/write) name of each volume. In this case, the
Backup System searches the Backup Database for the newest dump
set that includes a dump of either the read/write or the backup
version of the volume. It restores the dumps of that version of
the volume, starting with the most recent full dump. If, in
contrast, the name explicitly includes the ".backup" or
".readonly" extension, the Backup System restores dumps of that
volume version only.
<comments> ...
Is any other text. The Backup System ignores any text on each
line that appears after the volume name, so this field can be
used for notes helpful to the backup operator or other
administrator.
Do not use wildcards (for example, ".*") in the <machine>,
<partition>, or <volume> fields. It is acceptable for multiple
lines in the file to name the same volume, but the Backup System
processes only the first of them.
-extension <new volume name extension>
Creates a new volume for each volume specified by the -name or
-file argument, to house the restored data from that volume. The
Backup System derives the new volume’s name by appending the
specified string to the read/write base name, and creates a new
VLDB volume entry. It preserves the contents of each existing
volume. Any string other than ".readonly" or ".backup" is
acceptable, but the combination of the base name and extension
cannot exceed 22 characters in length. To use a period to separate
the extension from the name, specify it as the first character of
the string (as in ".rst", for example).
-portoffset <TC port offset>+
Specifies one or more port offset numbers (up to a maximum of 128),
each corresponding to a Tape Coordinator to use in the operation.
If there is more than one value, the Backup System uses the first
one when restoring the full dump of each volume, the second one
when restoring the level 1 incremental dump of each volume, and so
on. It uses the final value in the list when restoring dumps at the
corresponding depth in the dump hierarchy and all dumps at lower
levels.
Provide this argument unless the default value of 0 (zero) is
appropriate for all dumps. If 0 is just one of the values in the
list, provide it explicitly in the appropriate order.
-n Displays a list of the volumes to be restored if the flag were not
included, without actually restoring them. OUTPUT details the
format of the output. When combined with the -name argument, its
output is easily edited for use as input to the -file argument on a
subsequent backup volsetrestore command.
-localauth
Constructs a server ticket using a key from the local
/etc/openafs/server/KeyFile file. The backup command interpreter
presents it to the Backup Server, Volume Server and VL Server
during mutual authentication. Do not combine this flag with the
-cell argument. For more details, see backup(8).
-cell <cell name>
Names the cell in which to run the command. Do not combine this
argument with the -localauth flag. For more details, see backup(8).
-help
Prints the online help for this command. All other valid options
are ignored.
OUTPUT
If the -n flag is not provided, the command displays a unique task ID
number for the operation, in two places:
· In the shell window, directly following the command line.
· In the Tape Coordinator window, if the butc process was started at
debug level 1.
The task ID number is not the same as the job ID number displayed by
the backup jobs command when the backup volsetrestore command is issued
in interactive mode. The Backup System does not assign either type of
ID number until the restoration process actually begins.
When the -n flag is included, no task ID or job ID numbers are reported
because none are assigned. Instead, the output begins with a count of
the number of volumes to be restored, followed by a line for each dump
of a volume. For each volume, the line representing the most recent
full dump appears first, and lines for any subsequent incremental dumps
follow, ordered by dump level. The lines for a given volume do not
necessarily appear all together, however.
The format of each line is as follows (the output is shown here on two
lines only for legibility reasons):
<machine> <partition> <volume_dumped> # as <volume_restored>; \
<tape_name> (<tape_ID>); pos <position_number>; <date>
where
<machine>
Names the file server machine that currently houses the volume, as
listed in the VLDB.
<partition>
Names the partition that currently houses the volume, as listed in
the VLDB.
<volume_dumped>
Specifies the version (read/write or backup) of the volume that was
dumped, as listed in the Backup Database.
<volume_restored>
Specifies the name under which to restore the volume. The Backup
System only restores data to read/write volumes. If the -extension
argument is included, then the specified extension appears on the
name in this field (for example, "user.pat.rst").
<tape_name>
Names the tape containing the dump of the volume, from the Backup
Database. If the tape has a permanent name, it appears here;
otherwise, it is the AFS tape name.
<tape_ID>
The tape ID of the tape containing the dump of the volume, from the
Backup Database.
<position_number>
Specifies the dump’s position on the tape (for example, 31
indicates that 30 volume dumps precede the current one on the
tape). If the dump was written to a backup data file, this number
is the ordinal of the 16 KB-offset at which the volume’s data
begins.
<date>
The date and time when the volume was dumped.
One way to generate a file for use as input to the -file argument is to
combine the -name and -n options, directing the output to a file. The
IBM AFS Administration Guide section on using the Backup System to
restore data explains how to edit the file as necessary before using it
as input to the -file argument.
The output of this command includes only volumes for which the Backup
Database includes at least one dump record. The command interpreter
generates a message on the standard error stream about volumes that do
not have dump records but either are listed in the file named by the
-file argument, or appear in the VLDB as a match to a volume entry in
the volume set named by the -name argument.
EXAMPLES
The following command restores all volumes included in entries in the
volume set named "data.restore", which was created expressly to restore
data to a pair of file server machines on which all data was corrupted
due to a software error. All volumes are restored to the sites recorded
in their entries in the VLDB.
% backup volsetrestore -name data.restore
Starting restore
backup: task ID of restore operation: 112
backup: Finished doing restore
The following command restores all volumes that have entries in the
file named /tmp/restore:
% backup volsetrestore -file /tmp/restore
Starting restore
backup: task ID of restore operation: 113
backup: Finished doing restore
The /tmp/restore file has the following contents:
fs1.abc.com b user.pat
fs1.abc.com b user.terry
fs1.abc.com b user.smith
fs2.abc.com c user.jones
. . .
. . .
PRIVILEGE REQUIRED
The issuer must be listed in the /etc/openafs/server/UserList file on
every machine where the Backup Server or Volume Location (VL) Server is
running, and on every file server machine that houses an affected
volume. If the -localauth flag is included, the issuer must instead be
logged on to a server machine as the local superuser "root".
SEE ALSO
butc(5), backup(8), backup_addvolentry(8), backup_addvolset(8),
backup_diskrestore(8), backup_dump(8), backup_volrestore(8), butc(8)
COPYRIGHT
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
This documentation is covered by the IBM Public License Version 1.0.
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