I've got a 5gig gbk (It's from IB 5.6 under WinXP, but I figured this
question may apply to FB as well) that I attempted to restore. GBAK reports
that it's compressed, but when I look at the file in a hex editor part of
the file in the beginning is in the format:

TableName=<table>
Key Field Values:
FieldA=value
FieldB=value

Etc.

After about 100megs of that, the format appears to change to something a bit
more like encoded or compresses data.

Are there any utilities that can validate proper format of an IB or FB
backup file?

Thanks.