Re: [gentoo-user] CPU upgrade and LVM questions.

[Grant Taylor <gtaylor@gentoo.tnetconsulting.net>]

On 12/06/2018 02:27 AM, Dale wrote:
> From what I've read, I can use pvmove and pvremove to replace that drive. 
> Just tell pv to move the data and when done, remove the old drive. After 
> that, the new 6TB drive will be used in that PV and the 3TB drive can 
> be used for something else.  Is it really that easy or is there more to 
> it than that?  Pardon me but that doesn't sound complicated enough to me.

I've migrated multiple hundreds of TB of data this way.

In short:

1)  Partition the new drive(s) as desired.
2)  pvcreate /dev/$newPv
3)  vgextend $vgName /dev/$newPv
4)  pvmove /dev/$oldPv /dev/$newPv
5)  vgreduce $vgName /dev/$oldPv
6)  pvremove /dev/$oldPv

This does work well, even if the LV(s) are in use / file system(s) are 
mounted.

I have occasionally had issues where the system seems to not respond, 
despite the fact that it is doing what it's supposed to.  I wonder if 
it's related to the memory leak that J. Roeleveld was talking about.

Note:  I /do/ *STRONGLY* recommend that you do partition the new drive 
and /not/ pvcreate the entire drive.  —  Many of the data recovery tools 
/expect/ there to be a partition table.  Those that don't care are happy 
to work with a partition table.  I've seen others be in a very 
uncomfortable situation when they /didn't/ use a partition table. 
Simple easy thing to avoid painting yourself into a corner.



-- 
Grant. . . .
unix || die