Subject: Re: UVM/other problems for desktop users in current?
To: None <current-users@netbsd.org>
From: Dan Melomedman <dan%dan.dan@devonit.com>
List: current-users
Date: 12/19/2002 13:03:24
Ross Patterson wrote:
> On Wednesday 18 December 2002 02:31 am, Jukka Marin wrote:
> > On Wed, Dec 18, 2002 at 03:49:40PM +1100, Daniel Carosone wrote:
> > > For those experiencing this problem - are you running softdep?
> >
> > No.  Is it safe?  Does it help with NFS (server, client)?  I use it in
> > /tmp, but I haven't been brave enough to enable it elsewhere.

> To sum up, has it been definitively established that softdeps are safe?  Or 
> the converse?  I'm not qualified to answer, but I'd really love to know.

The way I understand it is they were designed to guarantee metadata
integrity, not data integrity. Something bad happens - your FS is not
corrupted, but some of the data may be gone. If you run an email server,
for instance, perhaps you shouldn't use them on the mail queue and mail
store, but it really is a tempest in a teapot. So many other bad things
can happen to your servers. That's why if you need good disk performance
a RAID controller with battery-backed cache is great performance and
safety-wise.