tech-userlevel archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: mounting by wedge name

On Wed, Mar 11, 2009 at 07:13:22PM -0500, David Young wrote:
> I am reopening this discussion because a year has past, and we are still
> without devfs or mount by wedge id, and I desperately want one or the
> other.  More remarks in-line:
> On Thu, Jan 10, 2008 at 01:09:25PM -0800, Jeff Rizzo wrote:
> > Bill Stouder-Studenmund wrote:
> >> On Sun, Dec 23, 2007 at 01:49:53PM -0800, Jeff Rizzo wrote:
> >>   
> >>> Certainly, I could see devfs removing the need for a lot of this - which
> >>> would make me happy.  Meanwhile...
> >>>     
> >>
> >> mjf's chimmed in, indicating something will happen w/ devfs. I've been  
> >> helping him with it, and wedges are the main reason I want devfs.
> >>   
> >
> > Yes, I think it makes sense to wait - especially since I found a number  
> > of other cases I would have had to deal with.
> Jeff, do you remember what those other cases are?

Some of the wedge discovery methods false positive, making it impossible
to use disks that actually have partition tables of other types.

Patient zero for this syndrome is the GPT method, which falses positive
on disks that once had a GPT but are now MBR partitioned with a BSD
disklabel in an MBR partition, making systems that ran fine this way
with 4.0 suddenly fail when upgraded because the system finds dk0
instead of wd0 and does not enumerate wd0's disklabel partitions.

There's also the problem with the original syntax for mount-by-wedge-id
making NFS filesystems from hosts named "wedge" fail.  I've worked two
places that had fileservers named "wedge"; anyway, backwards compatibility
failures like that are bogus.

Thor Lancelot Simon                               
    "Even experienced UNIX users occasionally enter rm *.* at the UNIX
     prompt only to realize too late that they have removed the wrong
     segment of the directory structure." - Microsoft WSS whitepaper

Home | Main Index | Thread Index | Old Index