kaikow wrote:1. If media is recorded using an ISO 9660 or ISO/EC 13346 conforming format, not to mention other well knon formats, NO software has any business restricting access to the media.
Oups, I should have been deeper in the details to clarify why we are doing this.
Yes, ISO and alike do not have such restriction, as well as udf reader from Microsoft won't have this restriction, and in fact, any read-only filesystem.
The purpose of protecting against intrusive commands from other software is that when you write to a media, the write is buffered and done later. But, as a write command might fail, the error will need to be deferred. This report of deferred error is done once the error occured the next time a command is received. This next command could be as well a read as a write command. The problematic case is when several host speaks at the same time to the same logical unit, then a host can potentially receive the deferred error from a command issued by another host. Argh, 2 problems:
- the host who receive the error believe his command failed, but in fact it's a command from another host which failed
- the host which error was "stolen" does not know about the problem, and will continue to run normally. This mean that if a write command failed, it will not be re-attempted or re-allocated to a safe block. Data loss!