Server Backup - What does it do?

[jone123]

I am curious what exactly does the backup do?. Does it write the file in a contiguous format or just an exact copy?

Does it do any maintenance while writing such as compacting?

The reason I am asking is we had a problem file last night that wouldn't open after starting the service. I restored the file from the previous backup and that opened fine.

Is it a good practice to restore files from backups periodically or just do the file maintenance on them periodically (compact and optimize)? Is there a difference?

Any input would be appreciated.

[Ender]

I'm pretty sure it just makes an exact copy (no maintenance is done).

If you have concerns about a file, open the file offline and do a Save a Copy As (Compressed). This is safer than the file maintenance options available in the Advanced versions of FileMaker.

[Steven H. Blackwell]

Very good point. The maintenance options [color:red]should never be used on a file that is suspected of having any damage to it at all.

Steven

[jone123]

Thank you for your response - I was just curious if the backup did anything since the backup copy of the file was able to open with no problem. I did some reading and FM says do not compact on a file that gets written to often, Optimize can be done on any file. So I guess Save as Compressed is the prefereed method over Compact. Its a little confusing, below is the official FM help:

About File Maintenance

With the File Maintenance tools, available only with FileMaker Pro Advanced, you can improve the performance of your database files. [color:blue]You can use the Compact File tool to remove free disk space from a file, reducing the file size and streamlining data access.

(This seems to conflict with area highlighted in blue below)

Use the Optimize File tool to improve file access speed by moving logically related data closer together. Both tools reduce disk-head movement. Improvements will be especially noticeable when you are using large files and performing finds or sorts, or executing scripts that operate on all records.

With the File Maintenance tools you can:

combine partially full disk pages and eliminate gaps in the data

defragment a file to make the physical arrangement of data match the logical arrangement

cancel either option without corrupting the file or losing the maintenance work done up to that point

perform file maintenance while hosting the file

(This is a surprise to me, I wouldn't think this is advisable)

Both File Maintenance tools work on the database file itself, without creating another copy. [color:blue]You should only use the Compact File tool on databases that will not have significant amounts of data added to them, because compression can actually increase fragmentation when data is added. You can use the Optimize File tool at any time, even on databases that will have data added to them.

The File Maintenance tools are fully documented in the FileMaker Pro Advanced Development Guide included with FileMaker Pro Advanced. (I didn't get this since I downloaded, would like to get this document)

Sorry for the long post but I'm really trying to know the file maintenance options and what are the best practices.

[Steven H. Blackwell]

Take a look at the Server tech Brief on the FMI web site:

http://www.filemaker.com/support/upgrade/techbriefs.html

Also take a look at the backUps White Paper on Wim Decorte's web site:

http://www.connectingdata.com/downloads.htm

Steven