Two DTs won't work together

Hi there,

I installed DT Pro on 2 Macs. Data base is residing in shared folder on the first Mac. I enabled sharing in DT and entered name and password into preferences under Server tab.
When I open that DB on second Mac (didn’t ask me for password or anything) it tells me that there are errors with DB and it should be re-built. Also next to DB name opened there is crossed icon of pencil. I can’t write anything to DB from Mac #2. I can see all the files created in Mac #1.
Also, if new record is created on Mac #1 it will not update on Mac #2 display.

What is a problem here?


The problem is that you cannot share a database with multiple machines using it at the same time. Normally you should see a message that the database is already in use.

Hi Annard,

Yes, that is what happens. Message pops up saying that DB is in use already then you can click OK to proceed.
I thought that message is only informative not really prohibitive so I always clicked OK. DB would open but then I encountered functionality problems.
What is then a purpose of having DB sharing there at all? Just to see what is in there? That is not bad either but comes short of real sharing.

There is no sharing of databases other than by using the Pro Office Server functionality. And that is read-mostly and you can only add data. Building a fully functional shared database is a major undertaking that we are not ready for at the moment.
The message is informative in the sense that if your database was closed incorrectly, it will also show this message. And therefore we allow you to proceed.
I would agree that it would be nicer if the machine that opened the database would be in the specific lock file as well and then we could compare these and make an extremely alarming message if people try to share the database with different machines.

Bad idea. I’m not certain whether you were using MobileMe or a shared folder on a local network.

Sharing a DT Pro database via MobileMe isn’t like sharing a word processing file or picture. Apple’s implementation of WebDAV will result in poor performance and a likelihood of database damage.

We recommend against synchronization of a database on MobileMe at this time. The developers are working on a plugin to mitigate problems.

LIkewise, sharing the same database on a local area network is a recipe for disaster.

DEVONthink databases are single-user databases. An attempt to access a database that is already in use, or that wasn’t properly closed, will generate a warning message. Simultaneous access of the same database by two copies of a DEVONthink application will probably result in database damage.

Recommendation: Stop your present practice, at least for now. Rebuild your database, or if you have a recent good backup, revert to the backup copy.

Some users report success using DropBox to synchronize databases on a desktop and laptop computer (others report problems). There are two major cautions: 1) always properly close a database on one computer before accessing it from a second computer; 2) never assume that synchronization is instantaneous — that’s a dangerous assumption when dumping lots of new content into a database, closing the database and opening the second computer’s database.

I can’t use (or trust) DropBox to synchronize databases on my desktop and laptop computers because I have a slow and flaky satellite broadband connection to the Internet. I have large databases, and sometimes make large changes in them. There are occasions (rain showers) when my download speeds are 12KB/second or less, and the upload speeds may be a fraction of that. It could literally take many hours for synchronization to be complete. For me, brute force copying between computers or running the database from a portable hard drive is much faster, more trustworthy and ultimately more convenient. In my circumstances, sneakernet rules!

Comment: “Cloud” synchronization via the Internet is an exciting prospect, and it’s getting a lot of attention. “Cloud” presence in computing may well be the Next Big Thing, and there’s a lot of hype about it. I say hype, because there continue to be reports of lost data and synchronization failures, on systems operated by major companies. Apple had serious teething problems with MobileMe. Microsoft very recently had some big problems with lost mobile computing data. A few years ago, when online backups first became available, I stored backups with two online companies. Both went bankrupt and the online backups disappeared. Fortunately, I had local copies of that data.

One of the fundamental principles of quality assurance (and of management) is that, if anything goes wrong, it’s your fault!

I like a “belt and suspenders” approach to protecting important data. Whatever backup system you use, provide redundant backups, with at least one set of backups totally under your control. Plan for
Bad Things that could happen (short of a major asteroid strike). Hard disks fail. Burglars steal computers. Buildings burn down. Online storage companies disappear.

I am using DropBox and found it super practical. I have 4 Macs in Toronto and one in Florida that share and use same folder at DropBox. Price lists, documents, quotes, all accessible changeable, instantly updateable … amazing. I use Mobile Me as well but mostly to keep Mac apps data in sync. Also, veeery useful.

I thought I could benefit from same with DT. In my mind if I opened same DB on two Macs (they are same DBs since they are synced), so if I add document in one, it will be automatically recorded in other one. That should happen if each record is small file by itself.
Now Bill is saying differently and I have to believe him. I am not a computer whiz, just a user.

I hope that it is not that hard to share same DB on 2 or more computers. We have QuickBooks software and it can be shared between 5 users at same time. If they did it, Devon should be able to do it.

Zack, there are limits. It is possible to have a database synchronized on more than one computer, given the cautions I mentioned. DropBox or a similar method can allow one to use the same database on their desktop and laptop computers, not simultaneously, but sequentially.

But you absolutely should not think about having that database opened simultaneously on multiple computers, with each user able to affect the content of the database as seen by other users. Only one user at a time.

That doesn’t mean that you can’t distribute a database to as many people as you like. That’s OK, as long as each copy of database is being accessed independently and is not communicating with any other copy of that database. If each of many users downloads a copy of the database and runs it in their Documents folder, that’s OK. Changes made to one copy will not affect any other copy.