Re: union mounts, mfs, and newsyslog

[Zafer AydoÄan <zafer%aydogan.de@localhost>]

On Wed, Jul 8, 2009 at 3:42 AM, matthew 
sporleder<msporleder%gmail.com@localhost> wrote:
> On Tue, Jul 7, 2009 at 9:11 PM, David
> Holland<dholland-current%netbsd.org@localhost> wrote:
>> On Tue, Jul 07, 2009 at 06:54:52AM -0400, matthew sporleder wrote:
>> Â> > I think the idea was to use a union mount instead of using unionfs,
>> Â> > although the cited line doesn't do that; you'd want
>> Â> >
>> Â> > Â Â mount -t mfs -o union swap /var/log
>> Â> >
>> Â> > This isn't the same thing, but it may serve your purposes if you don't
>> Â> > need the union to extend over subdirs.
>> Â>
>> Â> Oh, okay. ÂI read the mount(8) man page a few times and still didn't
>> Â> really get what it was saying until now.
>>
>> Any suggestions for improving it? :-/
>>
>
> I always have suggestions and opinions. Â:)
>
> Just add the example you gave me with a description like:
> "
> mount -t mfs -o union swap /var/log
>
> Creates an mfs mount on top of /var/log from the swap partition. ÂThis
> example does not descend into subdirectories. ÂSee mount_union(8) for
> more information on union mounts.
> "
>
> (patch below)
>
> --- mount.8.orig    Â2009-07-07 21:54:21.000000000 -0400
> +++ mount.8 Â Â 2009-07-07 22:01:34.000000000 -0400
> @@ -466,6 +466,20 @@
> Âfile system format in the first
> Â.Tn CD-ROM
> Âdrive.
> +.Pp
> +.Dl mount -t mfs -o union swap /var/log
> +.Ed
> +.Pp
> +Creates an
> +.Pa mfs
> +mount on top of
> +.Pa /var/log
> +from the
> +.Pa swap
> +partition. ÂThis example does not descend into
> +subdirectories. ÂSee mount_union(8) for more
> +information on union mounts.
> +
> Â.Sh DIAGNOSTICS
> ÂThe error
> Â.Dq Operation not supported by device
>

fyi:
this way you can use tmpfs over union. this is the only way to get
tmpfs over union working. i'm using this since a while. it isn't
documented anywhere.