* Mike Meyer <[EMAIL PROTECTED]> [010313 01:10] wrote:
> Helge Oldach <[EMAIL PROTECTED]> types:
> > Generally I'd say it's not a bad idea to have write caching on the disk
> > enabled - assuming that it is decently implemented. BTW, don't SCSI
> > disks use write cacheing as well? :-)
>
> Yes, they do. And it's recommended that you turn it off if you turn on
> softupdates. The driver doesn't do it for you, though.
Oh great... Perhaps the disk guru's can add some notes to the
sfotupdates docco about this? Or did I just miss this?
> I'd be interested to know details about why softupdates makes it more
> critical to have write caching off.
It's always critical to have write caching turned off to ensure filesystem
consistancy during an outtage.
Having write caching on is like having the disk ignore _any_
filesystem's attempt to do softupdates/logging/delayed-order-writes
because the disk _lies_ to the OS about when a write is safely on
the disk.
--
-Alfred Perlstein - [[EMAIL PROTECTED]|[EMAIL PROTECTED]]
Daemon News Magazine in your snail-mail! http://magazine.daemonnews.org/
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-stable" in the body of the message
