Data File Corruption
Some known causes of "MetaStock" format data file corruption are discussed below. Go to the end of the discussion for ways of recovering.
Data Files left open
Corruption can occur in the following circumstances -
If you are unable to access data files in a particular data sub-folder, check the folder using Windows to see if the following files are present -
- if your machine loses power or locks up during an update.
- if MetaStock™ is closed abnormally with data files still open.
If any or all of these files are present, delete them, taking care not to delete any other files.
The Equis/MetaStock Knowledge Base has advice on this issue here.
Simultaneous accessing of data files
If you have two or more charting applications, make sure you do not use them to view data at the same time, or file corruption may ensue.
Also, make sure that no charting or analysis application that can access the data is open when you are performing a data update.
Interference from Real-time Anti-Virus Scanning
Careful analysis of repeated file corruption events has shown that the problem could be attributed to real-time anti-virus scanning.
When real-time scanning was disabled, daily updates proceeded without error. When scanning was resumed, file corruption invariably recurred.
During an update, numerous files need to be opened and closed. Real-time anti-virus scanning attempts to check all of these files at approximately the same time as
the update is dealing with them. If the timing is slightly out, then the two applications are attempting to access the files at the same time and corruption occurs.
If you experience repeated instances of file corruption, it is strongly recommended that you exclude your data folders from real-time anti-virus scanning,
disable scanning entirely before an update commences, or even consider changing your Anti-Virus software.
File corruption may also be associated with the use of the "Favourites" feature in MetaStock™.
It is known that since MetaStock™ version 8, the file that stores information about Favourites (Favourites.dta) may become corrupted,
particularly when the results of Explorations are added to it. If there is a resulting problem with trying to open a security from Favourites,
the data folder that holds that security may also become corrupted (it appears as if the folder has been emptied).
If you are using the Favourites feature in MetaStock™, and finding that data sub-folders are being repeatedly emptied,
try deleting the file Favourites.dta (please be aware that you will lose all of your current Favourites).
A new Favorites.dta will be created when you start adding securities to the Favourites list again.
Once you have a fresh Favourites.dta in place, we recommend changing the database structure to remove alphabetical sub-folders.
Please see our FAQ on how to do this here.
Recovering from File Corruption
The best way to insure against potential corruption is to perform regular back-ups of your data folders with a Back-Up utility.
However, Windows also has its own built-in "System Protection" which you can use as a fall-back.
If you notice that a data folder has become corrupted, simply right-click on that folder, select "Restore previous versions" and then choose an earlier-dated version to restore.
Click here for an illustration
Windows System Protection has been available from Vista onwards (it is not available in XP). It should be enabled by default for your c: drive.
If your data is kept on another drive, such as the d: drive, configure System Protection to cover that drive by accessing System > System Protection from the Windows Control Panel.
What to Restore
If you restore an entire database, either from a back-up or from a Windows System Protection restore point, the corresponding updating program will "know" where to update from.
For Premium Data/Stocks - restore the entire "ASX", "SGX" or "US" folders.
For DataTools/Futures - restore the entire "Futures" folder.
For Premium Forex/Forex - restore the entire "Forex" folder.
Installing a fresh Data History
It may be that no sound back-up can be found to restore, or only a very old one. Or it may be that the corruption occurred quite a long time ago,
which would require the restoration of a very old back up and necessitate a very long update.
In these situations, you can always recover by installing a fresh history (by obtaining the relevant history installer from our Downloads area).
Notes on history re-installation are available here.
History installers are always available to current subscribers who purchased the corresponding history at some stage.