md /tmp and async mounts

[Giorgos Keramidas]

On 2006-06-01 17:06, Kris Kennaway <kris at obsecurity.org> wrote:
> On Thu, Jun 01, 2006 at 03:20:24AM +0300, Giorgos Keramidas wrote:
>
> [diff snipped]
>
> Thanks for the patch.
>
> > This doesn't make 'async' the default for all mdmfs mounts.
> >
> > Making async the default for mdmfs-based filesystems would
> > require a fair bit of changes to mdmfs, which would have to grow
> > mount-option parsing capabilities for the `optarg' of the -o
> > option and make sure that async is always added, unless mdmfs is
> > called explicitly with `noasync' in its -o option.
> >
> > Having said this, if this is considered a change we should make,
> > I can prepare a patch for mdmfs too.
>
> I think it should be the default.  I think we should also avoid using
> -M (malloc backing for md) in favour of swap backing because of the
> panic problems - this is too easy to trigger by accident and it makes
> FreeBSD look bad since it looks like a bug.

Ok, I'll prepare a patch that enables async and disables -M.  We should
also document the fact that tmpmfs="YES" and varmfs="YES" in rc.conf may
require the presence of at least one swap device by default, and point
the users to -M with a warning if they run FreeBSD without a swap device
but still want to use tmpmfs or varmfs :)