Monday, September 3, 2007

Recover Defective Drawing Files

Under some circumstances, it is possible that a drawing file becomes defective. This can result from hardware problems or transmission errors. If a drawing file is corrupt, you might be able to recover it.
  • Repair a Damaged Drawing File
    If a drawing file is damaged, you can recover some or all of the data by using commands to find and correct errors. When an error occurs, diagnostic information is recorded in the aclt.err file, which you can use to report a problem.
    A drawing file is marked as damaged if corrupted data is detected, or if you request that the drawing be saved after a program failure. If the damage is minor, sometimes you can repair the drawing simply by opening it. Otherwise, you can use the following:
    RECOVER command. Performs an audit on, and attempts to open, any drawing file.
    RECOVERALL command (LT2008 and higher). Similar to recover, it additionally operates on all nested xrefs. The results are displayed in the Drawing Recovery Log window.
    AUDIT command. Finds and corrects errors in the currently open drawing file.
  • Create and Restore Backup Files
    Backup files help ensure the safety of your drawing data. If a problem occurs, you can restore a drawing backup file. Computer hardware problems, power failures or surges, user mistakes, or software problems can cause errors in a drawing. By saving your work frequently, you can ensure a minimum of lost data if your system fails for any reason. If a problem occurs, you can restore a drawing backup file.
    In the Options dialog box, on the Open and Save tab, you can specify that backup files are created when you save drawings. If you do, each time you save a drawing, the previous version of your drawing is saved to a file with the same name and a .bak file extension. The backup file is located in the same folder as the drawing file.
    You can revert to your backup version by renaming the .bak file in Windows Explorer to a file with a .dwg extension. You may want to copy it to a different folder to avoid overwriting your original file.
  • Recover from a System Failure
    A hardware problem, power failure, or software problem can cause this program to terminate unexpectedly. If this happens, you can restore the drawing files that were open. If the program fails, you can save your current work to a different file. This file uses the format, DrawingFileName_recover.dwg, where DrawingFileName is the file name of your current drawing.
    After a program or system failure, the Drawing Recovery Manager opens the next time you start AutoCAD LT. Drawing Recovery Manager displays a list of all drawing files (DWG and DWT) that were open.
    Note: Unsaved drawings that are open at the time of an unexpected failure are not tracked by the Drawing Recovery Manager. Be sure to save your work after you begin, and regularly thereafter.
    For each drawing, you can open and choose from the following files if they exist:
    Note: The drawing, backup, and recover files are listed in the order of their time stamps—the time when they were last saved.
    Doubleclick a top-level drawing node listed under Backup Files to display up to four files as listed above. Right-click any node under Backup Files to display shortcut menu options.
    If you close the Drawing Recovery window before resolving all affected drawings, you can open Drawing Recovery at a later time with the DRAWINGRECOVERY command.