I've got FMS installed on Linux. The problem is that when i record something it
doesn't save anything. On Windows the same application works fine. In the
console it shows me that the flv was stored, but size = 0.

What might be the problem?

Thanks.

We had to create a streams directory beneath our application on Linux, this
might be because of our strict security model but might also apply to your case.

we let streams save in individual instance-directories like:

/opt/macromedia/fms/applications/<appname>/streams/<instancename>/

This behaviour can be changed with the StorageDir tag in your Application.xml
configuration file.