Backup fundamentals

[Peter2543]

What is a server backup doing, regarding the following:

- does it save a data base in a consistent state?

- is it possible to restore a backup? How and where to?

- is a data base consistent between backups, eg after a cache flush command?

- are backups done by simple copying, while FMS is up, unreliable?

- what happens to connected guests during a backup, perhaps even having running scripts and the like? what happens to backups scheduled as scripts are running?

Where does FMI says something about this, in docs or so? O'course I was looking for this but unfinding it, before post. (I did not search across forums. pointers to them would be answers.)

Peter

[LiveOak]

I'm not sure I know the exact answers to all these, but I'll take a shot:

1) It kind of depends on what you consider a consistent state. If you have started modifying an address and have not yet changed the zip code, you might not consider this a consistent state. FileMaker wouldn't save half of an entered field, so at a low level the "state" is consistent.

2) Backups are just copies of your files. To "restore", shutdown FM Server and replace the original file(s) with the backups.

3) Again, it depends upon what you mean by consistent.

4) You can't perform backups by simple copying, the files are "open" and you should not be able to copy them. Even if you manage to copy them, it isn't realiable and shouldn't be attempted. FM Server avoids this problem by suspending use of the files while it makes a copy.

5) Connected guests are "coffee cupped" (their operations are suspended). I don't know exactly what is allowed to complete before a user is suspended, but certainly not an entire script (some run for hours). You could do a test with a replace setting Status(CurrentTime), but my guess is that this operation would be suspended on some record in the middle of the operation. I'll also guess that FM flushes the caches on the server before backing up.

-bd

[Peter2543]

LiveOak here a few precisions.

First I did not find the issues of "consistent" and "restore" in the FMServer PDFs.

1) consistency can mean a lot of things. I thought of freezing all of a dozen or so files toghether, that form the data base. Not doing a backup of internally consistent fileA, then internally consistent fileB, but (fileA,fileB,...) together.

While thinking, consistency can also mean saving the state of scripts that run while the backup is being taken. I would need some scripts running to completion after a restore, even when the client isn'nt here anymore.

2) and 4) your answers are obvious -and my questions relating restore silly - except the FMS docs have been silent.

5) are the documentation or tech infos relating backups and scripts? I did not yet search except the FMS manual. There isn't a recommendation to manually stop all activity before backup. I found TI102516 and TI104463 give some tips.

6) there seem no server commands to do a clone or compressed copy automatically. Is there a good practice to this?

Peter