HP-UX Reference (11i v2 03/08) - 1M System Administration Commands A-M (vol 3)

f
frecover(1M) frecover(1M)
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.
The
fbackup index format now includes the file size in the first field; the previous format simply had the
’#’ character in that field. The implementation provides both forward and backward compatibility
between the old and new index formats. However, the file sizes are used in conjunction with the check-
points to increase selective recovery speed on DLT devices, so recovery of an
fbackup volume that does
not have the new index format will not see that performance gain.
When using a DDS tape written with the current release of
fbackup to do a partial recovery,
fre-
cover 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 pro-
gramming limitations that restrict users to this size, complete backups and recoveries of substantially
larger systems can cause a large amount of 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. However, if the entire backup
must be done with a single session, the user may encounter an error in frecover if there is not enough
virtual memory available. If this happens, the user might consider adjusting the maxdsiz parameter or
the swap space; both of these require a reboot.
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.
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.
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
frecover does not support QIC-120 and QIC-150 formats on QIC devices. 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.
HP-UX 11i Version 2: August 2003 − 4 − Hewlett-Packard Company Section 1M−−199