This note provides information about how users can recover files, which have inadvertently been deleted from Irwell, by using the backup and recovery interface, Legato Networker (Solstice) Backup.
Use of the Legato Networker (Solstice) Backup interface will usually only be on those (very rare!) occasions when you accidentally delete files you still wish to keep. The backup suite allows you to retrieve these files for yourselves, without recourse to Manchester Computing.
Files are generally backed up every night, so if a file is more than a day old, we should have a backup copy of it. We keep backup copies of files for up to one calendar quarter, after which the tapes are overwritten and the backup copies are no longer available. The index files are only kept on-line for 1 month, however, so if you wish to retrieve a backup that is more than 1 month old, you will need to contact Manchester Computing to do this.
In order to make reference to files as straightforward as possible, we have simplified the path names for users’ files to home/userid. Legato Networker uses absolute path names when backing-up files; this takes the form /fsxx/homey/userid. Our systems staff have, as a consequence, written scripts which translate your ‘pseudo’ path name to the absolute path name. It is these scripts (nwr and recov) which are described in the following paragraphs.
The command you type to invoke the GUI interface is:
nwr &
This presents you with a window, entitled ‘Solstice Backup Recover’. By default, the ‘directory tree’ shown will be your Irwell home directory, for example:
The process of recovering a file consists of three stages in general:
(b) Once the file(s) you wish to recover is/are displayed, you should Mark the file(s) for recovery by clicking in the little box to the left of the file name(s). It is also possible to mark directories (by clicking on the box next to the directory name) for recovery.
(c) Having marked the appropriate file(s), you then need to start the recovery by clicking on the Start button. The following ‘Conflict Resolution’ screen will appear, asking you what you wish to do in the event of file name conflict (that is, you may have a file with the same name as one that is to be retrieved, and the system needs to know what you wish to do).
Once you have instructed the system what you wish to do, click on "Ok". The following screen is displayed, informing you that the cartridge containing the data is being loaded. A message may appear saying that the requested files are not available on-line. This is nothing to worry about, it just means that the system is going to have to load up a different cartridge from the one that is currently on-line.
The recovery may take several minutes, as the robot has to locate the correct cartridge in the Digital Linear Tape (DLT) Library, load that cartridge and then spool to the correct location in order to retrieve the file(s). If you are recovering several files, they may of course be located on several different cartridges, and recovering these will obviously take longer.
When the file(s) have been successfully recovered, the following message is displayed in the 'Recover Status' window.
In the above window, three files were recovered successfully. Once you have received this ‘recovery successful’ message, you can click on the Cancel button to return to the main window. If you have finished recovering files, you can now exit from the program by selecting Exit from the File menu.
This interface also allows you to recover your files to a location other than from where they were deleted (that is, they can be recovered to another directory). You do this by selecting the Relocate option from the Options menu, which allows you to specify a different directory into which you can retrieve your file(s).
If you are marking several files in different directories for recovery, you can see all those marked by selecting Show Marked from the Mark menu before you Start the recovery.
It may be that you do not wish to retrieve the latest backup copy of your file, but an earlier version from before a specific date. In order to retrieve a file from an older version of the backup, you must first select the file. You do this by clicking on the little ‘file’ icon next to the file name (it goes dark when selected). The name of the file also appears at the top of the screen in the ‘Selection’ box. Once selected, you need to use the Versions command from the View menu. This presents you with a list of backups, taken on different dates, from which to choose. Mark the version you require by clicking on the ‘Mark’ box to the left of the version information, then select ‘OK’ when done. Proceed as normal.
There are fuller details given of this interface and its use available on-line by typing:
man nwrecover
If you are running on a standard Unix "line-mode" interface (that is, without X-windows access), it is still possible to recover files using a modified version of the Solstice
recover command. The modified command is recov. The format of the command is:recov
When you type
recov, you are placed in an interactive session. The prompt changes to:recover>
and the interface looks just like the normal Unix file system. You can use commands such as ls, cd, pwd, etc., to move around the file system. In this manner, you can move to the directory containing the file(s) which you accidentally deleted and then you can list the ‘backup’ files by typing ls. Wildcards, etc., can be used in the usual manner.
When you can see the names of the file(s) you want to recover, you must add them to the recover list by typing:
add
file_idsYou can now move to other locations and add other files to the recover list as required. To see the contents of the recover list at any time, just type:
list
When you are satisfied that all the files you wish to recover are in the list, type:
recover
to bring the files back on-line. When you have finished, type
quit at the recover> prompt to return to Unix.Alternately, if you know the full path name of a file, you can use the
recover command, which takes the format:recover [options] full_path_name
This method of recovery means that you are using ‘non-interactive’ line mode. You are strongly recommended to use the
recov command as described above.
(a) Example session using the line mode ‘interactive’ method.
Below is an example session of recovering the files mf641.doc, mf642.doc and mf643.doc from the directory mimasdocs. The instructions typed by our user are shown in bold:
irwell /home/zzavsro > recov
recover: Using nsrhost (backup.mcc.ac.uk) as server for irwell
recover: Current working directory is /fs04/home3/zzavsro/
recover> cd mimasdocs
recover> ls
mf641.doc mf641.pdf mf642.doc mf642.pdf mf643.doc mf643.pdf
mn203.doc…mn203.pdf
recover> add mf641.doc mf642.doc mf643.doc
3 file(s) marked for recovery
recover> list
/fs04/home3/zzavsro/mimasdocs/mf641.doc @ Wed Sep 15 09:31:34 1999
/fs04/home3/zzavsro/mimasdocs/mf642.doc @ Wed Sep 15 09:31:34 1999
/fs04/home3/zzavsro/mimasdocs/mf643.doc @ Wed Sep 15 09:31:34 1999
3 file(s) marked for recovery
recover> recover
Recovering 3 file into its original location
Total estimated disk space needed for recover is 19 MB.
Volumes needed (all on-line):
000011 at MC_STK1
Requesting 3 files, this may take a while...
./mf641.doc
./mf642.doc
./mf643.doc
Received 3 file(s) from NSR server ‘backup.mcc.ac.uk’
recover> quit
irwell /home/zzavsro >
(b) Recover a single file with known full path name, using the line mode ‘non-interactive’ method.
Note: If you are just recovering one file, and you know the pathname of that file, you can recover it directly by using the
-a option. Below is a recovery of the file mf641.doc, again from the subdirectory mimasdocs. It does not matter which subdirectory you are in when issuing the command, because the full path name must be specified. If you are not sure of your home directory’s full path name, you could type:/usr/local/sbin | grep
<userid>where <userid> is your MIMAS (Irwell) userid; for example:
/usr/sbin/mount | grep abcdefg
the output will look like this:
/home/abcdefg on /fs04/home3/abcdefg read/write on Thu Aug 12 11:53:25 1999
Actual Example
irwell /home/zzavsro > recover -a /fs04/home3/zzavsro/mimasdocs/mf641.doc
recover: Using nrshost (backup.mcc.ac.uk) as server for irwell
Recovering 1 file into its original location
Total estimated disk space needed for recover is 6 MB.
Requesting 1 file, this may take a while...
./mf641.doc
Received 1 file from NSR server ‘backup.mcc.ac.uk’
irwell /home/zzavsro >
The file has been recovered ... let’s check that it really is there.
irwell /home/zzavsro > cd mimasdocs
irwell /home/zzavsro/mimasdocs > ls
mf641.doc mf641.pdf mf642.doc mf642.pdf mf643.doc mf643.pdf
mn203.doc…mn203.pdf
Both of the above examples have been fairly simple and straightforward. It is also possible to recover files to a different directory from the one in which they were originally stored. If working interactively, use the relocate command, or if working non-interactively, use the -d option, which specifies a destination directory.
You can force recovered files to overwrite any existing files by using the force command if working interactively, or you can use the -f option if you are using a non-interactive command. These options are described in detail in the man pages, type:
man recover
for details. It is possible to recover files other than the latest "backed up" version by using the
versions and changetime commands if working interactively, or the -t option if working non-interactively. Again, you are referred to the on-line manual pages for fuller details of these commands and options.
If you have any problems using this system, then please contact through the normal channels, or if you wish, directly through the Helpline on:
tel
email:
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