File Corruption- possible causes and prevention.

Resolving The Problem

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This list does not include all possible causes of file corruption but offers suggestions for the most common causes only. There is no way to tell what causes a particular file to be corrupted or 'backtrack' the file to a stable state, so it is strongly suggested that regular backups of all files be made. All applications on your pc are subject to file corruption.

1. One of the most common causes of corruption is that files are being stored or accessed on a fragmented drive. Run a scandisk and defrag to optimize the drive and clear up lost clusters. This may also help with performance as the free harddrive space will now be contiguous.

2. System shutdowns, power surges, cntrl+alt+deleting while a file is open, can all be causes of file corruption. Save often to prevent data loss. Back up all files. Work with one application at a time if resources are low. Do not reboot until you are certain the system is hung, and that it is not simply still processing its tasks.

3. If a file is a copy of a copy of a copy etc, this can cause
corruption to 'spread'. If the first file contained any problems this has now been copied to the other files. Do not base new files on ones that have had problems. Use templates if applicable.

4. Viruses may cause symptoms similar to file corruption. Run an up to date virus check on the system.

5. If a template is corrupt, the reports based on that template may also inherit that corruption. In this case use the back up template or if it is one of the templates we supply, delete and reinstall a clean version. The same is true of catalogs.

6. There have been cases of email causing problems in files. Confirm your email is not affecting the report, by testing with other files.

7. If you have determined that the model is corrupt, save it as a MDL and reopen it.

8. It is possible for an INI file to become corrupt. Renaming that file ( for example the cognos.ini) and re-installing or copying from a machine that works may resolve this issue.

Usually, corruption is not stated as a cause for a file to fail until all other possible reasons have been determined NOT to be the cause. Symptoms of corruption include: General Protection Faults, freezing or hanging, strange symbols or behavior, inability to open or save a file, erroneous error messages or a inability to copy. Symptoms of a corrupt catalog include invalid login errors for users, invalid govenor settings, all the above errors, failure to open or connect to the database. Search for our support document titled ' Troubleshooting General Protection Faults' using the key words Tips and Troubleshooting. This provided tips on GPF's.