On 6/24/19 12:12 PM, Mick wrote:
LVM-RAID uses the kernel's mdraid,
Yep.
You can get device mapper command(s) to show the internal / under the
hood MD devices.
I feel like what LVM does to mirror (RAID 1) devices is complex. You
end up with non-obvious LVs that are then raided together to create
another virtual block device that is what you see as the LV.
There are options about where and how metadata is mirrored. Some of
which is stored in the VG and others is stored in another small hidden
LV specifically for this purpose. Which itself can be configured to
have multiple copies.
At least that's how I remember things from about five years ago.
but with less tools to manage the RAID configuration than mdadm offers:
That's because the standard LVM tools make calls to the kernel to manage
things. I never /needed/ anything other than the LVM tools to
administer LVM RAID. But I think that you can find the expected things
under device mapper et al. if you know where to go look.
When I say "hidden", it seems as if the traditional LVM tools simply
don't expose LVs with specific naming patterns unless you go looking for
them. Much like dot files are ""hidden by default, but there if you
know where and how to look.
--
Grant. . . .
unix || die
