Backup and Restore Process 11/21/97 DRAFT version ============================== server:/usr/local/lib/DUMP E = full EPOCH I = Incremental yymmdd EDUMPTAB contains log information COMMANDS USED: -------------- restore -tvf /dev/nrst8 > lt.lst # generates listing of table of contents on tape grep 0662664 lt.lst # finds specific file (0662664) mt -f /dev/hrst8 rewoffl # rewinds tape off line mt -f /dev/nrst8 fsf 1 # fast forward to file 1 mt -f /dev/nrst8 asf 1 # absolute skip to file 1 restore ivf /dev/nrst8 # restores tape =============================== in data vault: currently 12 tapes for full dump in Data Center: log held in server:/usr/local/lib/DUMP/EDUMPTAB go to Qualstar silo select STOP button open silo rewind tape that's in silo: mt -f /dev/nrst8 rewoffl insert tape to be restored mt -f /dev/nrst8 fsf 1 # mount and fast fwd to file 1 cd /disk_vol3/rest092897 # move to location for restore, nothing there? restore ivf /dev/nrst8 ls cd cdds cd hpuser cd cdserv cd lt add spls_065149.1.c.Z ... to extract next vol 1 set owners & permissions return to restore mode - quit mt -f /dev/nrst8 rewoffl return Qualstar Stacker to sequential mode (close door) Note: loads from bottom up, never goes back down ================================= man page RESTORE: ================================= RESTORE(8) MAINTENANCE COMMANDS RESTORE(8) NAME restore, rrestore - incremental file system restore SYNOPSIS /usr/etc/restore -irRtx [ filename ... ] DESCRIPTION restore restores files from backup tapes created with the dump(8) command. options is a string of at least one of the options listed below, along with any modifiers and arguments you supply. Remaining arguments to restore are the names of files (or directories whose files) are to be restored to disk. Unless the h modifier is in effect, a directory name refers to the files it contains, and (recursively) its sub- directories and the files they contain. OPTIONS i Interactive. After reading in the directory informa- tion from the tape, restore invokes an interactive interface that allows you to browse through the dump tape's directory hierarchy, and select individual files to be extracted. See Interactive Commands, below, for a description of available commands. r Restore the entire tape. Load the tape's full contents into the current directory. This option should only be used to restore a complete dump tape onto a clear filesystem, or to restore an incremental dump tape after a full "level 0" restore. For example: example# /usr/etc/newfs /dev/rxy0g example# /usr/etc/mount /dev/xy0g /mnt example# cd /mnt example# restore r is a typical sequence to restore a "level 0" dump. Another restore can be done to get an incremental dump in on top of this. R Resume restoring. restore requests a particular tape of a multivolume set from which to resume a full restore (see the r option above). This allows restore to start from a checkpoint when it is interrupted in the middle of a full restore. t Table of contents. List each filename that appears on the tape. If no filename argument is given, the root directory is listed. This results in a list of all files on the tape, unless the h modifier is in effect. (The t option replaces the function of the old dumpdir program). Sun Release 4.1 Last change: 7 September 1988 1 RESTORE(8) MAINTENANCE COMMANDS RESTORE(8) x Extract the named files from the tape. If a named file matches a directory whose contents were written onto the tape, and the h modifier is not in effect, the directory is recursively extracted. The owner, modifi- cation time, and mode are restored (if possible). If no filename argument is given, the root directory is no filename argument is given, the root directory is extracted. This results in the entire tape being extracted unless the h modifier is in effect. Modifiers Some of the following modifiers take arguments that are given as separate words on the command line. When more than one such modifier appears within options, the arguments must appear in the same order as the modifiers that they apply to. a archive-file The dump table of contents is taken from the specified archive-file instead of from a dump tape. If a requested file is present in the table of contents, restore will prompt for the tape volume to be mounted. If only contents information is needed, for example when the t option is specified, or the i option is specified without a corresponding extract request, no dump tape will have to be mounted. c Convert the contents of the dump tape to the new filesystem format. d Debug. Turn on debugging output. h Extract the actual directory, rather than the files that it references. This prevents hierarchical res- toration of complete subtrees from the tape. m Extract by inode numbers rather than by filename to avoid regenerating complete pathnames. This is useful if only a few files are being extracted. v Verbose. restore displays the name of each file it restores, preceded by its file type. y Do not ask whether to abort the restore in the event of tape errors. restore tries to skip over the bad tape block(s) and continue as best it can. b factor Blocking factor. Specify the blocking factor for tape reads. By default, restore will attempt to figure out the block size of the tape. Note: a tape block is 512 bytes. Sun Release 4.1 Last change: 7 September 1988 2 RESTORE(8) MAINTENANCE COMMANDS RESTORE(8) f dump-file Use dump-file instead of /dev/rmt? as the file to restore from. If dump-file is specified as `-', restore reads from the standard input. This allows, dump(8) and restore to be used in a pipeline to dump and restore a file system: example# dump 0f - /dev/rxy0g | (cd /mnt; restore xf -) If the name of the file is of the form machine:device the restore is done from the specified machine over the network using rmt(8C). Since restore is normally run by root, the name of the local machine must appear in the .rhosts file of the remote machine. If the file is specified as user@machine:device, restore will attempt to execute as the specified user on the remote machine. The specified user must have a .rhosts file on the remote machine that allows root from the local machine. s n Skip to the n'th file when there are multiple dump files on the same tape. For example, the command: example# restore xfs /dev/nrar0 5 would position you at the fifth file on the tape. USAGE Interactive Commands restore enters interactive mode when invoked with the i option. Interactive commands are reminiscent of the shell. For those commands that accept an argument, the default is the current directory. ls [ directory ] List files in directory or the current directory, represented by a `.' (period). Directories are appended with a `/' (slash). Entries marked for extraction are prefixed with a `*' (asterisk). If the verbose option is in effect, inode numbers are also listed. cd directory Change to directory directory (within the dump-tape). pwd Print the full pathname of the current working direc- tory. add [ filename ] Add the current directory, or the named file or direc- tory directory to the list of files to extract. If a directory is specified, add that directory and its files (recursively) to the extraction list (unless the Sun Release 4.1 Last change: 7 September 1988 3 RESTORE(8) MAINTENANCE COMMANDS RESTORE(8) h modifier is in effect). delete [ filename ] Delete the current directory, or the named file or directory from the list of files to extract. If a directory is specified, delete that directory and all its descendents from the extraction list (unless the h modifier is in effect). The most expedient way to extract a majority of files from a directory is to add that directory to the extraction list, and then delete specific files to omit. extract Extract all files on the extraction list from the dump tape. restore asks which volume the user wishes to mount. The fastest way to extract a small number of files is to start with the last tape volume and work toward the first. verbose Toggle the status of the v modifier. While v is in - effect, the ls command lists the inode numbers of all entries, and restore displays information about each file as it is extracted. help Display a summary of the available commands. quit restore exits immediately, even if the extraction list is not empty. FILES /dev/rmt8 the default tape drive dumphost:/dev/rmt8 the default tape drive if called as rre- store /tmp/rstdir* file containing directories on the tape /tmp/rstmode* owner, mode, and timestamps for direc- tories ./restoresymtable information passed between incremental restores SEE ALSO dump(8), mkfs(8), mount(8), newfs(8), rmt(8C) DIAGNOSTICS restore complains about bad option characters. Read errors result in complaints. If y has been specified, or the user responds y, restore will attempt to continue. If the dump extends over more than one tape, restore asks the user to change tapes. If the x or i option has been specified, restore also asks which volume the user wishes to mount. There are numerous consistency checks that can be listed by restore. Most checks are self-explanatory or can "never happen". Common errors are given below. Converting to new file system format. A dump tape created from the old file system has been loaded. It is automatically converted to the new file system format. filename: not found on tape The specified file name was listed in the tape direc- tory, but was not found on the tape. This is caused by tape read errors while looking for the file, and from using a dump tape created on an active file system. expected next file inumber, got inumber A file that was not listed in the directory showed up. This can occur when using a dump tape created on an active file system. Incremental tape too low When doing an incremental restore, a tape that was written before the previous incremental tape, or that has too low an incremental level has been loaded. Incremental tape too high When doing incremental restore, a tape that does not begin its coverage where the previous incremental tape left off, or one that has too high an incremental level has been loaded. Tape read error while restoring filename Tape read error while skipping over inode inumber Tape read error while trying to resynchronize A tape read error has occurred. If a file name is specified, then its contents are probably partially wrong. If an inode is being skipped or the tape is trying to resynchronize, then no extracted files have been corrupted, though files may not be found on the tape. resync restore, skipped num blocks After a tape read error, restore may have to resyn- chronize itself. This message lists the number of blocks that were skipped over. BUGS restore can get confused when doing incremental restores from dump tapes that were made on active file systems. Sun Release 4.1 Last change: 7 September 1988 5 A "level 0" dump must be done after a full restore. Because restore runs in user mode, it has no control over inode allocation; this means that restore repositions the files, although it does not change their contents. Thus, a full dump must be done to get a new set of directories reflecting the new file positions, so that later incremental dumps will be correct. Sun Release 4.1 Last change: 7 September 1988 6 server#