[Veritas-vx] Boot time volume restrictions

[Doug Hughes]

On Fri, 20 Feb 2004, Mark Andrews wrote:

> I'm reading the VxVM 3.5 Solaris admin guide and am confused about some
> of the
> terminology regarding boot-time volume restrictions.
>
> Under the heading "Boot-time Volume Restrictions", the thirtd bulleted
> item states:
>
> Restricted mirrors of volumes on the root disk have overlay partitions
> created for them.
> An overlay partition is one that exactly includes the disk space
> occupied by the
> restricted mirror. During boot, before the rootvol, varvol, usrvol and
> swapvol volumes
> are fully configured, the default volume configuration uses the overlay
> partition to
> access the data on the disk.

I believe this is a reference to the fact that the rootdisk
(traditionally) is encapsulated, so those mirrors are restricted from
grow/ etc in the normal sense.
>
> What's a "restricted mirror"? A mirror of the one plex which constitute
> the rootvol,
> swapvol and possible other volumes in the rootdg?
>
each individual volume.

> Connected with this is confusion over what the "overlay partition" is
> and what its
> used for. Is the overlay partition similar to a disk VTOC, but instead
> it describes
> the starting block and length of the volume mirrors?

it's the 'slice' data recorded in the VTOC for that volume so that you
can deencapsulate.