Am 06.03.2012 18:25, schrieb Neil Bothwick:
> On Tue, 6 Mar 2012 16:32:56 +0000, Stroller wrote:
> 
>>> … I initially want to replace the 3x1TBs with a single 3TB drive but
>>> i've never removed/replaced a drive in an LVM setup before. I think I
>>> understand how it is done, using pvmove …   
>>
>> Or you could just format and mount the new drive and use `cp`.
> 
> Thereby instantly removing the benefits of LVM and making it almost
> impossible to extend the space by adding another drive when needed.
> 

I don't think so. vgextend the volume group with the new disk, lvcreate
a new volume using only extents from the new disk, copy data over to it,
swap mount points, done.

Plus points: Removes fragmentation of the old file system. Also probably
faster.

> To the OP, pvmove is perfectly safe as it does a copy;verify;delete on
> one small block of extents at a time. It also ensures that any new writes
> while pvmove is running go to the new drive, so you can still use the
> system while moving (try doing that with cp :).
> 
> 

Wait, are we talking about a system disk (root and stuff)? I was under
the impression that it's just a data dump. Of course, with system
partitions and other media that cannot be handled read-only for a longer
time, pvmove or lvchange are the better options.

Regards,
Florian Philipp