hpux 10.20 - frecover (1)
NAME
frecover - selectively recover files
SYNOPSIS
/usr/sbin/frecover -r [-hmosvyAFNOX] [-c config] [-f device] [-S skip]
[-E extarg]
/usr/sbin/frecover -R path [-f device]
/usr/sbin/frecover -x [-hmosvyAFNOX] [-c config] [-e path] [-f device]
[-g graph] [-i path] [-S skip] [-E extarg]
/usr/sbin/frecover -I path [-vy] [-f device] [-c config]
/usr/sbin/frecover -V path [-vy] [-f device] [-c config]
DESCRIPTION
frecover reads media written by the fbackup(1M) command. Its actions
are controlled by the selected function -r, -R, -x, -V, or -I.
The function performed by frecover is specified by one of the
following letters:
-r The backup media is read and the contents are loaded
into the directories from which they were backed up.
This option should only be used to recover a complete
backup onto a clear directory or to recover an
incremental backup after a full level-zero recovery
(see fbackup(1M)). This is the default behavior.
-x The files identified by the -i, -e, and -g options (see
below) are extracted or not extracted from the backup
media. If a file to be extracted matches a directory
whose contents have been written to the backup media,
and the -h option is not specified, the directory is
recursively extracted. The owner, modification time,
and access control list (including optional entries,
unless the -A option is specified) are recovered. If
no file argument is given (including an empty graph
file), all files on the backup media are extracted,
unless the -h option is specified.
-I path The index on the current volume is extracted from the
backup media and is written to path.
-V path The volume header on the current volume is extracted
from the backup media and is written to path. The
following fields from the header are extracted in the
format label:value with one pair per line.
Magic Field On a valid fbackup
media it contains the
value FBACKUP_LABEL.
On a pre-10.20 fbackup
media it contains
FBACKUP LABEL.
Machine Identification This field contains
the result of uname
-m.
System Identification This field contains
the result of uname
-s.
Release Identification This field contains
the result of uname
-r.
Node Identification This field contains
the result of uname
-n.
User Identification This field contains
the result of
cuserid(3S).
Record Size This field contains
the maximum length in
bytes of a data
record.
Time This field contains
the time fbackup was
started.
Media Use This field contains
the number of times
the media has been
used for backup.
Volume Number This field contains a
# character followed
by 3 digits, and
identifies the current
volume in the backup.
Checkpoint Frequency This field contains
the frequency of
backup-data-record
checkpointing.
Fast Search Mark Frequency This field contains
the number of files
between fast search
marks for backups made
with DDS tape drives.
Index Size This field contains
the size of the index.
Backup Identification Tag This field is composed
of 2 items: the
process ID (pid), and
the start time of that
process.
Language This field contains
the language used to
make the backup.
-R path An interrupted full recovery can be continued using
this option. frecover uses the information in file
path to continue the recovery from where it was
interrupted. The only command line option used by
frecover with this option is -f. The values in path
override all other options to frecover. Note also that
only full recoveries are restarted with this option,
because no history of include or exclude lists is
stored in the restart file. If a partial recovery
(i.e., using the -x option) is interrupted then
restarted with this option, frecover continues
recovering where the partial recovery left off, but
restores all files on the backup media beyond this
point.
The following characters can be used in addition to the letter that
selects the desired function:
-c config config specifies the name of a configuration file to be
used to alter the behavior of frecover. The
configuration file allows the user to specify the
action to be taken on all errors, the maximum number of
attempts at resynchronizing on media errors (-S
option), and changing media volumes. Each entry of a
configuration file consists of an action identifier
followed by a separator followed by the specified
action. Valid action identifiers are error, chgvol,
and sync. Separators can be either tabs or spaces. In
the following sample configuration file, each time an
error is encountered, the script
/var/adm/fbackupfiles/frecovererror is executed. Each
time the backup media is to be changed, the script
/var/adm/fbackupfiles/frecoverchgvol is executed. The
maximum number of resynchronization attempts is five.
error /var/adm/fbackupfiles/frecovererror
chgvol /var/adm/fbackupfiles/frecoverchgvol
sync 5
-e path path is interpreted as a graph to be excluded from the
recovery. There is no limit on how many times the -e
option can be specified.
-f device device identifies the backup device to be used instead
of the default /dev/rmt/0m. If device is -, frecover
reads from standard input. Thus fbackup(1M) and
frecover can be used in a pipeline to backup and
recover a file system as follows:
fbackup -i /usr -f - | (cd /mnt; frecover -Xrf -)
If more than one output file is specified, frecover
uses each one successively and then repeats in a
cyclical pattern. Patterns can be used in the device
name in a way similar to file name expansion as done by
sh(1). The expansion of the pattern results in all
matching names being in the list of devices used. A
device on the remote machine can be specified in the
form machine:device. frecover creates a server
process, /usr/sbin/rmt, on the remote machine to access
the tape device. If /usr/sbin/rmt does not exist on
the remote system, frecover creates a server process
from /etc/rmt on the remote machine to access the tape
device. The pattern matching capability does not apply
to remote devices. Only half-inch 9-track magnetic
tapes or DDS-format tapes can be remote devices. The
fast search capability is not used when accessing
remote DDS-format devices.
-g graph graph defines a graph file. Graph files are text files
and contain the list of file names (graphs) to be
recovered or skipped. Files are recovered using the -i
option; thus if the user wants to recover all of /usr,
the graph file contains one record:
i /usr
It is also possible to skip files by using the -e
option. For instance, if a user wants to recover all of
/usr except for the subgraph /usr/lib, the graph file
contains two records:
i /usr
e /usr/lib
If the graph file is missing, frecover exits with an
error message. An empty graph file results in
recovering all files on the media.
-h Extract the actual directory, rather than the files
that it references. This prevents hierarchical
restoration of complete subtrees from the backup media.
-i path path is interpreted as a graph to be included in the
recovery. There is no limit on how many times the -i
option can be specified.
-m Print a message each time a file marker is encountered.
Using this option, frecover prints a message each time
either a DDS setmark, a file marker, or a checkpoint
record is read. Although useful primarily for
troubleshooting, these messages can also be used to
reassure the user that the backup is progressing during
long, and otherwise silent, periods during the
recovery.
-o Recover the file from the backup media irrespective of
age. Normally frecover does not overwrite an existing
file with an older version of the file.
-s Attempt to optimize disk usage by not writing null
blocks of data to sparse files.
-v Normally frecover works silently. The -v (verbose)
option causes it to display the file type and name of
each file it treats.
-y Automatically answer yes to any inquiries.
-A Do not recover any optional entries in access control
lists (ACLs). Normally, all access control
information, including optional ACL entries, is
recovered. This option drops any optional entries and
sets the permissions of the recovered file to the
permissions of the backed up file. Use this option
when recovering files backed up from a system with ACLs
on a system for which ACLs are not desired (see
acl(5)).
-F Recover files without recovering leading directories.
For example, this option would be used if a user wants
to recover /usr/bin/vi, /usr/bin/sh, and /etc/passwd to
a local directory without creating each of the graph
structures.
-E extarg Specifies the handling of any extent attributes backed
up by fbackup(1M). The -E option takes the following
keywords as arguments:
warn Issues a warning message if extent
attributes cannot be restored, but
restore the file anyway.
ignore Do not restore extent attributes.
force Issue an error message and do not
restore the file if extent attributes
cannot be restored.
Extent attributes cannot be restored if the files are
being restored to a file system which does not support
extent attributes or if the file system's block size is
incompatible with the extent attributes. If -E is not
specified, extarg defaults to warn.
-N (no recovery) Prevent frecover from actually recovering
any files onto disk, but read the backup as if it was,
in fact, recovering the data from the backup, producing
the same output that it would on a normal recovery.
This option is useful for verifying backup media
contents in terms of validity (block checksum errors
are reported), and contents (a listing of files can be
produced by using the -N and -v options together).
Note that the listing of files produced with the -N and
-v options requires the reading of the entire backup,
but is therefore a more accurate reflection of the
backup's contents than the index stored at the
beginning of the backup (which was created at the start
of the backup session, and is not changed during the
course of the backup).
-O Use the effective uid and gid for the owner and group
of the recovered file instead of the values on the
backup media.
-S skip frecover does not ask whether it should abort the
recovery if it gets a media error. It tries to skip
the bad block or blocks and continue. Residual or lost
data is written to the file named by skip. The user
can then edit this file and recover otherwise
irretrievable data.
-X Recover files relative to the current working
directory. Normally frecover recovers files to their
absolute path name.
EXTERNAL INFLUENCES
Environment Variables
LC_COLLATE determines the order in which frecover expects files to be
stored in the backup device and the order in which file names are
output by the -I option.
LC_MESSAGES determines the language in which messages are displayed.
If LC_COLLATE and LC_MESSAGES are not specified in the environment or
is set to the empty string, the value of LANG is used as a default for
each unspecified or empty variable. If LANG is not specified or is
set to the empty string, a default of "C" (see lang(5)) is used
instead of LANG. If any internationalization variable contains an
invalid setting, frecover behaves as if all internationalization
variables are set to "C". See environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
WARNINGS
For incremental backups created prior to installing HP-UX Release 8.0,
or for recoveries that do not begin with the first volume (such as
when, reading tape 3 first), it is possible for the preceding
directories to a recoverable file to not be on the media. This can
happen, for example, if the directories did not change since the last
full backup. If frecover encounters a file on the backup that should
be recovered, but it has not recovered the file's parent directories
from the backup, it prints a message stating that the recovery will
continue with that file, and attempts to create the file's parent
directories as needed.
Use of frecover does not require special privileges. However, if a
user does not have access permission to a given file, the file is not
recovered.
Network special files are obsolete. Therefore, frecover cannot
restore these files. A warning message is issued if an attempt is
made to recover a network special file, and the file is skipped.
When using a DDS tape written with the current release of fbackup to
do a partial recovery, frecover attempts to use the DDS fast-search
capability to find files on the tape more quickly. In order to do
this, however, frecover needs to create an in-memory copy of the
index, and mark the files on that index which it needs to recover
before actually reading through the tape to find the files. This is
done when the first index is read from the tape, and accounts for a
period of time just after recovery is begun where the tape is inactive
while this in-memory index is constructed. The larger the index is,
the longer this period lasts.
The utility set comprised of fbackup and frecover was originally
designed for use on systems equipped with not more than one gigabyte
of total file system storage. Although the utilities have no
programming limitations that restrict users to this size, complete
backups and recoveries of substantially larger systems can cause a
large amount system activity due to the amount of virtual memory (swap
space) used to store the indices. Users who want to use these
utilities, but are noticing poor system-wide performance due to the
size of the backup, are encouraged to back up their systems in
multiple smaller sessions, rather than attempting to back up the
entire system at one time.
Note that when recovering files with access-control lists, the ACL
entries are stored on the backup as user login names. If a login name
cannot be found in the password file, the file is recovered without
its ACL, and an error is printed. In order to fully recover files
backed up with ACLs, the password file (/etc/passwd) must be recovered
before attempting to recover any desired ACLs.
Care should be taken to match the names specified by the include and
exclude options with the names in the index on the tape. Since the
files are stored on the backup in lexographic order as defined by the
LANG or LC_COLLATE environment variable, frecover uses the exact path
names to determine when a partial recovery is complete, and when an
earlier tape needs to be loaded. If a user's specification of a file
to be recovered is misspelled, this may cause confusing messages, such
as frecover asking for the previous volume, when volume one is
mounted.
DEPENDENCIES
SS Series 700/800 frecover is not supported on QIC devices with QIC-
120, and QIC-150 formats. If frecover is attempted for these formats,
frecover fails and the following message is displayed :
mt lu X:Read must be a multiple of 512 bytes in QIC 120 and QIC
150
AUTHOR
frecover was developed by HP.
FILES
/dev/rmt/0m Default backup device.
SEE ALSO
cpio(1M), dump(1M), fbackup(1M), restore(1M), rmt(1M), tcio(1M),
acl(5).