[linux-lvm] LVM /dev and /proc problems and change proposal

[Heinz J. Mauelshagen]

On Sun, Jun 25, 2000 at 10:01:30PM +1200, Dale Kemp wrote:
> > But It dissallows the user to do it and there's still plenty of free namespace
> > to find a meaningfull name for the Volume Group.
> 
> I'm refering to the future when a new device gets added that just might
> clash with a volume group name that a user has chosen. And we don't know
> what users are going to call their volume groups and we don't know what
> device names will be created in the future.

vgrename(8) is able to address that.

> 
> > There's a preprocessor definition LVM_DIR_PREFIX in the code, which
> > supports this already.
> 
> So I see. The simplest solution is to change this default prefix, and have the
> lvm stuff self-contained in its own subdirectory.

Yes.
Please give it a try and tell me if it works.

> Even without the name
> clash this is just tidier, already /dev is very wide but not very deep.
> 
> > I don't like both, because they break the hierarchy of LVs (like virtual
> > partitions) contained in VGs (like virtual disks containing physical disks).
> 
> Fair enough :-)  Just throwing some ideas around.

;-{)

> 
> Can I `propose' that simply by changing the default (LVM_DIR_PREFIX) in the
> original LVM code and we begin `standardizing' now the LVM directories.
> 
> eg.
> 
>   /dev/lvm/ (all previuos
>     |
>     +-- lvm [c:109,0] (need to change constant LVM_DIR in "liblvm.h" too]
>     |
>     +-- vdisk1/
>          |
>          +-- group [c:109,0]
>          +-- lvol1 [b:58,0]
>          +-- lvol2 [b:58,1]

Sure.
Please try the LVM_DIR_PREFIX change.

> 
> 
> > > Also I think there should be a sub-directory for lvm itself in /proc
> > > ie. /proc/lvm/lvm instead of /proc/lvm.
> >
> > Yep.
> > Already on the TODO list.
> > I share your point of view in regard to /proc.
> 
> The need for /proc/lvm/... is simular to that for /dev/lvm/...

More or less.

/proc/* is for programs to parse the contained information.

Therfore its not primarily addressing a real name clash problem
but the answer to the request for easy parsing.

> 
> -- Dale.

-- 

Regards,
Heinz      -- The LVM guy --

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Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Bartningstr. 12
                                                  64289 Darmstadt
                                                  Germany
Mauelshagen at Sistina.com                           +49 6151 7103 86
                                                       FAX 7103 96
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