Pref Doctor Documentation
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Saves your preferences...
If you lose your preferences, settings, or registrations when your device resets then Pref Doctor might be able to help...
Thanks for trying Pref Doctor! - I hope it helps!
If your device doesn't have NVFS (non-volatile file system) you won't need Pref Doctor
Current Devices that have NVFS and where Pref Doctor might help are
- Treo 650
- LifeDrive
- Tungsten E2
- Tungesten T5
- Tungesten X
- Zire Z22
When Palm One (now Palm) introduced the NVFS it was really buggy. Now its only a bit buggy - but one of those bugs seems to kill preferences.
The NVFS allows Palm Devices to use the same kind of memory as in an sd card to store applications and data. This has the advantage of letting Palm use cheap memory chips which use less battery. However to run applications, it needs to copy the applications and databases to traditional memory (the cache). To make this work - the operating system has to do some complex swapping of data between the cache and the NVFS. Unfortunately one of the side effects of this is that the preferences database seems to get corrupted and destroyed in some circumstances.
Pref Doctor offers three cures that aim to help!
There is an old Palm Os bug which goes something like this
- Application registers with the exchange manager to handle a particular type of file
- Application is moved to the sd card or deleted
- Exchange manager gets the file, goes looking for the app and can't find it. In its confusion, it kills the preferences database.
Pref Doctor cures this by cleaning out the exchange manager entries relating to any apps that aren't in RAM (it does this when every app exits)
More details of the bug at the Palm Source site.
If you're runnign apps from the sd card - then this might well reduce resets for you.
Simple - and probably the best cure. This doesn't actually stop any problems, it just makes a copy of the preferences database every time it is changed. If there is a reset, then at the very beginning of the reset sequence, Pref Doctor checks that your preferences are still there. If they're not - Pref Doctor restores the old preferences.
The cunning bit is that it does this even before the other apps get to respond to the reset request, so they see their normal preferences and are able to do what they're supposed to do (like setting alarms).
It doesn't stop the reset - but it should stop the nasty loss of preferences.
The More details page gives you extra details on the various preferences databases.
These are
- Current Database: The one that is being used by the system now
- Backup: The latest backup made by Pref Doctor
- Replaced: If PrefDoctor has to load the backup preferences after a reset, then it will copy the newly created preferences database that it replaces. This is the 'replaced' database.
The Mod# shows the modification number of the database. This is incremented every time the database is changed.
The Created info shows the created data&time of the backup.
The two restore buttons allow you to restore these databases should you wish.
One thing the operating system has to do from time to time is clean out all the applications in the cache to make room for new ones (flushing the cache). Unfortunately, it seems that sometimes it cleans out the preferences database and in the process kills it.
Pref Doctor locks the preferences database so it can't be flushed. It then makes sure that when each app ends, the preference database is copied back into the NVFS so that your changes are not lost at a reset.
Some users have reported a significant reduction in resets as a result of this cure - and without the resets, they're not losing preferences. It doesn't work 100% though.
For people using DBCache, there certainly seem to be problems in some circumstances (annoyingly it doesn't seem clear cut - the same settings give one user resets and work fine for another!).
| Your Situation | Suggestion |
| You use apps from the SD card | Cure 1 is probably a good idea for you. If you want to get technical and check what applications are registering for the exchange manager, then the excellent Palm Internals can help you dig into the details |
| You have never lost preferences on reset. | You're lucky! The best bet might be to change nothing! Alternatively, cure 2 will give you a backup should things deterioriate. |
| You occasionally lose preferences | Cure 2 is probably best for you. It should make sure you don't lose resets. Cure 3 is probably overkill; there's a chance it will stop the resets from happening, but it's having to do a lot of work to achieve that and may have other side effects. |
| You lose preferences all the time | You need cure 2! Try Cure 3 as well. If it seems to reduce the resets, then keep it. If it doesn't then at least cure 2 is saving your preferences! |
Contact
Please do send comments / suggestions.
If you have problems, please first read the troubleshooting section and the instructions in the app. If you're still stuck, please contact me as above.
Enjoy,
Rob