On Thu, Jun 15, 2000 at 07:16:43PM -0500, Peter Seebach wrote:
> In message <200006152118.RAA26602@ghost.whirlpool.com>, Andrew Gillham writes:
> >Under the Qmail FAQ there is question of reliability.  It says not
> >to use softupdates with qmail.  Why is this a problem?  I thought
> >that that all filesystem operations were guaranteed to be safe by
> >the "ordered" nature of soft updates?
> 
> "safe", yes, but there's no promise that a given write will have actually
> taken place physically in the event of a crash, only that the set of writes
> which has happened is expected to be consistent.  qmail may be depending on
> certain operations being really-synchronous.

And, if the user has asked for a synchronous write (with fsync() or
O_SYNC), those operations still are.  And, without softdep, the user
never had a guarantee that they would be *unless* he used fsync() or
O_SYNC anyway.

This is all really much ado over nothing.

-- 
Thor Lancelot Simon	                                      tls@rek.tjls.com
	"And where do all these highways go, now that we are free?"