Does Time Machine back up an open DevonThink Pro database?

Still have a bit of confusion about how DEVONthink Pro Office interacts with the hourly Time Machine backup, as well as my once a day clone of my entire hard drive using SuperDuper. If either or both of my primary databases are open (which they most often are) are they being backed up incrementally? Or do any changes to the databases send a signal to Time Machine that the ENTIRE database needs to be backed rather than just the changes? In which case having TM back it up would be quite unwieldy due to the size of the databases.


DEVONthink doesn’t interact with the TimeMachine backup. TimeMachine starts at a specific point in time and determines what files have changed. It then starts backing up when the file list has been gathered. So there is no signal sent to TimeMachine form DEVONthink.

I understand this, but what my initial question was getting at is this: does DTP allow Time Machine to back up JUST the changed files or does it require a backup of the ENTIRE DTP database? Also, does Time Machine back up an OPEN DTP database at all? I don’t see this spelled out anywhere in the DEVONtechnologies support info. Thanks.

DEVONthink doesn’t allow Time Machine anything. Time Machine does what it does without interacting with DEVONthink. Time Machine knows absolutely nothing about DEVONthink and your data. In my own experience, databases “backed up” by Time Machine are often in an indeterminate stage, unreliable, and unusable. Personally, I wouldn’t bother to restore a database from Time Machine. Others in the forum report different results. YMMV.

The only completely trustworthy backup of a DEVONthink database is one performed with the database closed – with the entire database package copied to a secure destination.

I agree with korm that the most reliable backup of a database would be when it is closed (except for database archives produced by DEVONthink Pro or Pro Office). That’s because a backup made while a database is open could “miss” activity being processed in memory and subsequently saved to disk.

However, I use Time Machine, and have tested backups made while the database was open, and never found a problem. I do most of my work on a MacBook Air or MacBook Pro, and when I “dock” the laptop after working on battery power I always close DEVONthink Pro Office to make the first Time Machine backup of changes.

I have a Promise Pegasus 3 TB RAID unit that connects via Thunderbolt, and has very fast read/write speeds. As it held the Time Machine backups for my MacBook Air and all my databases and other files, I decided to transfer everything to my new MacBook Pro Retina from Time Machine. That went perfectly. I verified all the databases and compared their Database Properties on both machines after the file transfers. No problems at all (I’m using the User Account transferred from the MacBook Air on the MacBook Pro).

A weakness of Time Machine and other backup utilities is that there’s no check for possible errors in a database. It’s up to me to manually run Tools > Verify & Repair occasionally, perhaps every week or so on databases that I’ve modified, to ensure they re in good shape. I do that, although it has been a very long time since I’ve seen an error report. After running Verify & Repair I’ll manually run Tools > Backup & Optimize to update the internal backup in the database; that’s also good for performance after adding new content.

My backup strategy consists of still another layer of backup, as I contemplate the possibility that something could happen to all of my computer equipment including Time Machine backups. The ultimate layer consists of database archives that are periodically updated on a portable hard drive that’s stored offsite at a safety deposit box at my bank. The database archives that can be created by DEVONthink Pro or Pro Office produce the smallest possible complete archive of a database. This procedure first checks for errors and will stop and notify the user if errors are found, so that they can be eliminated before making a backup.

I think remote, off site backups are very important just as an insurance policy. I use Crashplan which is excellent and it backs up over the internet continuously. So if you should have a disaster in your home (robbery, fire etc) your files are safely stored up in another location.

I use Time Machine. Today I opened up a document and made a mistaken change, before saving it.

How to I find the previous version of that document, in DT onTime Machine ? Document was created months ago, so it has been backed up.

Thank you

Here’ what I do. It’s somewhat belts-and-supenders, but one can’t be too careful with ones data.

  1. Close ALL databases and quit DEVONthink
  2. Locate the database in your folders, and enter Time Machine
  3. Retrieve the database from Time Machine, but save it as copy somewhere else – do not damage the current copy.
  4. Open the database you just retrieved, in DEVONthink.
  5. Find the document(s) you wanted, and copy them/it to the desktop
  6. Close ALL databases and quit DEVONthink
  7. Delete the database you retrieved from Time Machine and empty the trash
  8. Open the working copy of the database and copy the retrieved document(s) from the desktop

You might be tempted to browse inside the database package of the database instance stored in Time Machine. Personally, I like to avoid that. It’s easy to mess up and you might once again need a reliable copy of the Time Machine copy of the database at some time.

Korm, just to be sure I understand the implication…

A doc, not indexed (i.e. not external), needs to be restored. If I find its location within the maze of the database’s folder hierarchy, then it’s not advisable to go into TM, look in that particular folder and restore an earlier version? Is that because the database’s index of the internal files would no longer apply to what the restored file’s data now contains?

I should add that DTPO is closed when not in use for a specific function and I do weekly Verify & repair.

This is merely my opinion – and DEVONtechnologies might offer different advice. How DEVONthink manages the internals of the database, metadata files, etc., is opaque. If I change the internals of a database package I’m shooting in the dark. It may work; it might not. But, why take the risk when I don’t have to? The content of my databases involved thousands of hours of work and I don’t do fiddly things with those files. On the rare occasions where I need to retrieve data from Time Machine, I do it in the most conservative way I can.

Like korm, I tend to be cautious. I wouldn’t want to “restore” my existing database to an earlier backup from Time Machine, as I would probably lose a lot of data. In the hypothetical case, I’m looking for a particular document that’s probably in a Time Machine backup.

If I’m going to have to open that earlier version of the database under DEVONthink, I’ll first close the database that will be temporarily restored, go to the Finder and make a zipped copy of it. After restoring from the early version and finding and exporting the document I was looking for, I would close the restored database, delete its file and unzip the previously zipped current version of the database.