[linux-lvm] Mirror Capabilities on LVM2

[linux-lvm] Mirror Capabilities on LVM2

[Kelly Sauke]

I saw in the archives a post about LVM2 version 2.01.12 having some mirror
capabilities.  Reading through the changelog it doesn't really explain what
those capabilities are. I've downloaded 2.01.14 and installed it but alas the
man pages don't have anything about the -m option either.  So, can someone
quickly explain (or point me to documentation) what mirror options/capabilites
are currently available and what options are planned?  I'm most curious about
whether the ability to attach one lv to another and form a mirror and then split
the mirrored lv into two distinct lvs that are both mountable (similar to a
snapshot only a completely separate lv).  We use this capability within veritas
all the time when moving disk around online and its really the only thing
holding us back from scrapping veritas in favor of lvm.

Re: [linux-lvm] Mirror Capabilities on LVM2

[Alasdair G Kergon]

So far, you can just create a new mirror LV with (e.g.) lvcreate -m1.
(needs at least 3 PVs in the VG)

Eventually you'll be able to use lvconvert to convert an existing 
LV into a mirror.  Kernel-side improvements are on they way too
(device error-handling/read balancing).

> whether the ability to attach one lv to another and form a mirror and then split
> the mirrored lv into two distinct lvs that are both mountable (similar to a
> snapshot only a completely separate lv).  

We're planning to support that, yes.

Alasdair
-- 
agk@redhat.com