Nuno Teixeira wrote: > I understand the basic concept of the folowing techs: softupdates, disk > write cache and ata tags. > > My question is: > > It is safe to use softupdates + write cache + ata tags (IBM disk)? > > I read someware that it not safe to use softupdate + write cache > (without ata tags) and if it is not safe why FreeBSD 5.0 ships with them > enabled?
See the discussion of 3 weeks ago with one of the engineers from Maxtor, on this list. The short answer is that the drive does not honor tags on a commit to stable storage, before returning the request as satisfied, and that's because on a write, ATA doesn't support disconnect with tagged commands. As to why write caching is on be default, there's a lot of going back and forth on that, and it's flipped state maybe 4-5 times, so far. The short answer is that ATA drives are pig-slow with write caching disabled, and users find that unacceptable. -- Terry To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
