Recovering a Database

This information is divided into two sections.

Note: Before you attempt to recover a database, it is strongly recommended that you create a backup copy of the work files .wrk.isis and .wrk.isix.

Recovering a Vulcan Database

Recovery of design databases or layers may be required if there is a system failure, or if the database has been corrupted due to limited disk space. Any changes that you make to existing design data is actually performed on a copy of the data contained in the work file (.wrk). The work file also contains all currently selected layers, including those from other databases and data converted layers (for example drill holes) as well as any design work that is created in new layers.

You can specify the location of this workfile through the Miscellaneous section of the Tools > Preferences option. The real data is only updated when you perform a save operation. Thus it is possible to save lost work by reloading the contents of this work file.

The recovery process is only available when:

the database is not actively locked ( ), and
the database is not currently loaded ( ), and
the database is headered, and
the equivalent work file/database exists

If the database is located on a network drive, then the associated work file may not be accessible if the system failure occurred on a different machine and the user at the time was using the 'alternative work file directory' preference. In this case the work file exists but will/may be on a local drive on the original machine and not accessible over the network.

Refer to the Miscellaneous section of the Tools > Preferences option for more on the 'alternative work file directory' preference.

To recover a design database after a system failure:

If the Workbench is still running, right-click on the locked database file (in the Vulcan Explorer window) and select Recover from the displayed context menu.

If both Vulcan and the Workbench are not running;

Without removing any lock files, restart Vulcan.
Select the design database that you want to open, i.e. the design database that was open when the system failure occurred.
From the displayed warning message, check the Recover data check box before pressing the Unlock and Open button.
Select the File > Load Recovered Layers option to load the recovered data into the original database
Select the Save button (on the Standard toolbar) to save the design database.

To recover a design database that has been corrupted due to limited disk space:

If database index and database error messages suddenly start appearing, while using or opening Vulcan, then you may have a corrupt database or layer. The cause of this may be a lack of disk space. The operating system will still attempt to perform an operation even if there is insufficient disk space.

To determine whether the cause of corruption was indeed lack of disk space, check the available space, before attempting any of the following recovery methods.

If only one layer is corrupt, then rename or move the .dgd.isix file to another name or directory, and ensure that free disk space is available of at least twice the size of the database. Generate the index file through using the Compress and Rebuild option (Vulcan Explorer application), Rebuild or Compress Database (under the Design & Digitising menu of Vulcan) or the Compress & Rebuild option (under the Design > Utilities submenu of Vulcano).
Write out the database as an ASCII file using the Generate Reloadable Database Listing option (under the Design & Digitising menu of Vulcan) and then reload it using the Reload Database Listing option (also under Design & Digitising). Corresponding Vulcano options are Create Listing and Reload Listing (under the Design > Utilities submenu.
Reload the database from a backup tape.

Recovering an Isis Database

Should a system failure cause the Workbench to crash while you are editing a database through the Isis Editor, then any modified objects will not have been saved. These edits reside within an edit database and can be recovered by performing the following steps:

Restart the Workbench.
Start the Isis Editor.
Select the File > Open Database option and choose the database. A panel will then appear warning you that the database is locked from the previous session. Press the Remove Lock and Open button.
The database will open and a panel will appear warning of the presence of an edit database from the previous session. There are three options:
Cancel
Close the database.
Recover
The Isis Editor will connect to the existing edit database, restoring any changes made to objects in the previous session. These modifications are not automatically saved into the database and so you may proceed with further modifications or choose to save them.
Discard
The Isis Editor will create a blank edit database, discarding any unsaved modifications from the previous session.

Changes to the object that was current at the time of the crash may be lost. Deleted objects will reappear after a recovery is performed and will need to be deleted again.

The standard isis_lock file that is generated upon opening a database prevents multiple people from establishing the same working database. Even if a file is locked for editing, other people still have read-only access to that database. However, for certain operations, a stricter isis_wlock file is created upon opening a database. The isis_wlock file restricts both read and write access to the database by anyone other than the primary user.