Monday, August 1, 2011

Lion - Server Dataloss Explained

I have had some questions about how exactly this works and what the ramifications are. I've put together a little screen capture that demonstrates the problem in detail. We have tested this with both Snow Leopard Server and Lion Server. Watch this video and you will see exactly what the problem is:

Lion Dataloss on Servers

What needs to happen is that Apple needs to change the API for versions to disable the functionality entirely on shared volumes. With it disabled the app would have to revert back to the "you have unsaved changes, save or quit" behavior of all prior versions of MacOS.

I recognize that Apple is trying to make things easier for the novice, but at the same time the ability to do non-destructive edits is something that people use on the mac all the time. It is a fundamental feature of a computer. What versions is doing is removing the ability for the user to control when they write changes to a document. With a personal system this isn't the end of the world because versions allows you to "revert to save" but with networked volumes this will only end in tears.

If you require that the user first duplicate the document, there will quickly be thousands of duplicate documents on the server that users did not throw away. This is also a big problem.

There has to be an answer to this, and it's going to have to come from Apple.

Joel

5 comments:

Anonymous said...

Can't you just not give everyone write permissions on the share? If you have originals you want to keep, it seems like the safest bet. They will get the dialog to save somewhere else.

renewingmind said...

Sure, I could make it so nobody could write on the share. Then they would stop using the server altogether and I lose a valuable resource. Servers have worked fine with MacOS for more than twenty years. It is only with Lion that suddenly there is this new problem.

Anonymous said...

What it appears to me is that the program that is opening the actual picture is the issue and not entirely the OS. If the program opens it up and crops it are you positive that it is not saving it even though you did not execute a save. The reason I say it is not entirely the OS is because what ever you are using to open the picture may have to be updated for Lion to work. Just a thought. As far as using Lion as a server there are better choices out there in my opinion.

renewingmind said...

The program I am using is Preview, software that Apple ships with the OS. It has been updated for Lion, and that is the problem. Lion includes two features: auto-save and versions that are meant to remove the need to ever manually choose to save. This is a great idea (if you can turn it off IMHO) for a single user. My video shows what happens when you try to apply these concepts in a network environment. They don't work.

The problem is not with lion as a server either, it is with Lion as a client. We are not currently using Lion server, although we did test this problem with Lion server to see if they had some magic to stop this problem.

We have experience with Linux, Windows Server 2008 R2 and Mac OS X. Nothing beats Mac OSX Server for price vs. performance except Linux, and Mac OSX Server is a lot easier to administrate and works better for file services with mac clients, which is 100% of our network.

Joel

Anonymous said...

This is not expected behaviour and definitely not good. We use AFP here and this alone would stop us upgrading to Lion clients.