[linux-lvm] LVM pretends it has more space than it actually has

[Gijs]

Ah like that. Ok, I can't imagine I typed such a command, but I guess I 
can never really know. But let's say I did, would it be possible to 
somehow retrieve the data from that volume? By increasing the underlying 
raid-5 maybe? Or is it forever lost?

On 19-9-2011 20:48, Ray Morris wrote:
> The symptoms you are presenting, the "missing" 1MB are similar
> to if someone did this in the past:
>
> mdadm --create /dev/md1 /dev/sd[ab]1
> pvcreate /dev/md1
>
> Then later someone did this:
> mdadm --assemble /dev/md1 /dev/volgroup/firstLV
>
> The VG, or the reported size of the PV, is 1MB smaller than
> the device the PV is on, due to the metadata. If the RAID array,
> or rather any raid array, were created on /dev/sda1, for
> example, but then later activated using /dev/volgroup/LV,
> mdadm would report that the device was 1MB too small, which is
> exactly the message you are getting.