Re: NetBSD 8: Install on an LVM partition

[Michael van Elst <mlelstv%serpens.de@localhost>]

On Sun, Feb 24, 2019 at 12:34:34AM -0800, John Nemeth wrote:
> } LVM is mostly a userland thing and requires a running system to start. This
> 
>      In what way is it "mostly a userland thing"?  I don't believe
> this statement is true.

The whole concept of volume groups and logical volumes including the
corresponding meta data only exist in userland.

All this is translated into one or more translation tables that are
interpreted by the device mapper. You can use the device mapper
completely without LVM, it doesn't know what volumes are.



> } seen anyone doing this. You can find details (for cgd) at
> } https://wiki.netbsd.org/security/cgdroot/.
> } 
> } Everything else could be logical volumes, but on a single disk system you
> } would need to create some hybrid partitioning scheme which is hardly worth
> 
>      This is very simple to do as outlined in my other note.

Sure. You can add a traditional partition to be used by LVM, different
from how LVM is normally used. Not that difficult, but also not very
useful.


> } the effort. Using LVM for data disks (including things like /home) works
> } fine.
> } 
> } Please also note that our LVM only implements a subset. We still lack
> } a mirror target, so LVM raid or even just moving LVs online is not yet
> } supported.
> 
>      This much is true.  dm(4) is old and somewhat limited.  Also,
> although lvrename kinda works, I have found it to be problematic.

I'm working on it.



Greetings,
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."