[linux-lvm] Removing a (potentially unused?) PV from a VG

[linux-lvm] Removing a (potentially unused?) PV from a VG

[Harold Pimentel]

Hi all,

So, I have the following setup:

- Ubuntu 12,04
- 1 6TB physical volume (the one with data) [ext4]
- 1 13TB PV (no data... I think?) [ext4]

Here is the story...

- I created an ext4 on the 13TB PV, added the 13TB to the VG to make a
13TB volume group.
- Everything went fine and then I ran:

Code:

resize2fs /dev/volgroup/volume


And to my surprise.. I couldn't resize past 16TB ! (crap! should have
checked this first!).

So, nothing happened.. Now what I want to do is remove the 13TB PV
from the VG and do something else with it... but I get the following
error:


Code:

sudo vgreduce -t home_volume_group /dev/sdc1
  Test mode: Metadata will NOT be updated.
  Physical volume "/dev/sdc1" still in use

I don't remember the message, but I was going to try to use pvmove to
move stuff off of /dev/sdc1 and it failed stating something like "No
available extents"... which I don't even expect to have anything
written to that disk since nothing was written after the install.

How can I safely remove this PV from the VG?


Thanks a bunch!

Harold

Re: [linux-lvm] Removing a (potentially unused?) PV from a VG

[Marian Csontos]

On 02/08/2013 09:18 PM, Harold Pimentel wrote:
> Hi all,
>
> So, I have the following setup:
>
> - Ubuntu 12,04
> - 1 6TB physical volume (the one with data) [ext4]
> - 1 13TB PV (no data... I think?) [ext4]
>
> Here is the story...
>
> - I created an ext4 on the 13TB PV, added the 13TB to the VG to make a
> 13TB volume group.

Moment. Why creating ext4 on the PV first?
You added PV to VG first, I guess.

> - Everything went fine and then I ran:
>
> Code:
>
> resize2fs /dev/volgroup/volume
>
>
> And to my surprise.. I couldn't resize past 16TB ! (crap! should have
> checked this first!).

OK, so did it resize to 16TB, right? So now you have 16TB FS over two 
PVs: 6TB + 10TB. You need to downsize the FS first.

Also, when resizing LVs, it is safer to use fsadm, to avoid common 
problem where people shrink LV before FS.

>
> So, nothing happened.. Now what I want to do is remove the 13TB PV
> from the VG and do something else with it... but I get the following
> error:
>
>
> Code:
>
> sudo vgreduce -t home_volume_group /dev/sdc1
>    Test mode: Metadata will NOT be updated.
>    Physical volume "/dev/sdc1" still in use
>
> I don't remember the message, but I was going to try to use pvmove to
> move stuff off of /dev/sdc1 and it failed stating something like "No
> available extents"... which I don't even expect to have anything
> written to that disk since nothing was written after the install.

If above still fails, try `pvmove --alloc anywhere /dev/sdc1`. It may help.

-- Marian

>
> How can I safely remove this PV from the VG?
>
>
> Thanks a bunch!
>
> Harold
>
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