Subject: Re: Changed mount_mfs behavior?
To: Julio Merino <>
From: Andrew Cagney <>
List: current-users
Date: 09/20/2002 14:10:03
> On Friday 20 September 2002 19:50, Andrew Cagney wrote:
>> The behavior of mount_mfs appears to have changed in 1.6.  Previously,
>> given:
>> 	mount_mfs /dev/wd0b /tmp
>> it would take the max size from wd0b.  Now it appears to ignore it -
>> leaving me with a very small /tmp.  Is this correct?
> I've always seen this behavior, since I started using NetBSD... probably
> around 1.5Z. Guess it's okay.

(the behavour depends on the userland mount command not the kernel).  It 
changed between 1.5x and 1.6x.  The old man page read:

The parameters to mount_mfs are the same as those to newfs.  If the -T 
flag is specified
(see below), the special file is unused.  Otherwise, it is only used to
read the disk label which provides a set of configuration parameters for
the memory based file system.  The special file is typically that of the
first swap area, since that is where the file system will be backed up
when free memory gets low and the memory supporting the file system has
to be paged.  If the keyword ``swap'' is used instead of a special file
name, default configuration parameters will be used.  (This option is
useful when trying to use mount_mfs on a machine without any disks).

> I manually pass the size value with the -s=100m option.

Yes, some trial and error and I found similar can be added to fstab.  An 
example of how ``-'' options can be used in fstab would be useful.

Anyway, having to manually specify the file system size is a pain.