Re: DIOC{G,S}STRATEGY not implemented for all disk devices

[jnemeth%victoria.tc.ca@localhost (John Nemeth)]

On Jun 19,  3:10pm, Reinoud Zandijk wrote:
} On Wed, Jan 16, 2008 at 10:21:27PM -0800, John Nemeth wrote:
} > } There seem to be several almost-identical implementations, in
} > } sys/dev/dksubr.c, sys/dev/ld.c, and sys/dev/ata/wd.c; an implementation
} > } in sys/dev/scsipi/cd.c that always returns EIO; and implementations in
} > 
} >      I'm not sure it makes sense for cd.c since that is a read-only
} > device and isn't truely random access.
} 
} I have code here for cd.c that actually permits setting the strategy; not 
} used anymore though but for dvd+rw/dvd-ram its a truely random access 
} device allthough it wouldn't be fast.

     Do these devices work using concentric cylinders similar to the
way magnetic media works, or do they use the one long spiral track the
way most optical media (and old vinyl records) work?

}-- End of excerpt from Reinoud Zandijk