Re: Moving LVM volume?

[Joel Rees <joel.rees@gmail.com>]

On Fri, Jan 2, 2015 at 3:37 PM, Bob Proulx <bob@proulx.com> wrote:
> Frank Miles wrote:
>> I recently added a new hard drive to my home system.  I decided to use it
>> to create an all-new bootable 'jessie' system.  I created a partition
>> table that I thought would be flexible:
>>    /dev/sdb1         /   (root) {7G}
>>    /dev/sdb2         /swap       {4GB}
>>    /dev/sdb3         /oldjunk    {1G}
>>    /dev/sdb4  extended      {remainder}
>>    /dev/sdb5     LVM        {one large volume}
>
> Why didn't you put / on LVM?  Because you put your /boot there?
>
> I know this is too late for you but I recommend putting /boot on the
> first partition.

Maybe not, now that you mention it.

>  Just /boot and nothing else.  Getting the initrd and
> the kernel loaded I still think is less trouble when they exist on a
> simple filesystem and outside of lvm.  Then use the rest of
> the disk as physical volumes for lvm.  For you I might suggest:
>
>   /dev/sdb1         /boot   {256M}
>   /dev/sdb4  extended       {remainder}

Why extended? I generally put my LVM partition straight in a DOS
primary partition, unless I needed more than three non-LVM partitions
for some reason.

>   /dev/sdb5  LVM PV         {one large volume}
>
> [...]
>> Is there some method that I've overlooked?
>
> Yes.  Simply add those partitions as additional PVs to the VG volume
> group.  If you have freed up their data then increase the size of your
> volume group by using them as physical volumes.  Then with more space
> in your volume group you can allocate the space to your logical
> volumes.  There is no need to move the start of sdb5 PV down.
>
>   pvcreate /dev/sdb3
>   vgextend vg1 /dev/sdb3

Woops. My memory's bad sometimes. Yeah. There is no need to move stuff
inside the LVM.

You can cobble together logical partitions out of physically separated
regions of disk.

Slightly fragmented logical partitions are not even that much of a
performance penalty. I even ran a Fedora install with a /var partition
that consisted of about four separate fragments for a couple of years.

Sorry, Frank. it may not be as bad as I painted it.

-- 
Joel Rees