[CentOS] LVM newb needs assistance

Thu Oct 8 16:42:59 UTC 2009
Giovanni P. Tirloni <tirloni at gmail.com>

On Oct 8, 2009, at 1:33 PM, Allie Daneman wrote:

> I'm new to Linux and LVM coming from a BSD and Solaris background so I
> apologize up front if there are good docs for this that I'm missing.  
> After
> googling around and going through the LVM Admin docs for CentOS I  
> have a
> few questions about an issue I have.
>
> Somehow either I did it out of stupidity or the installer  
> automagically
> installed LVM and included both drives I have on this server. It's
> configured as 1 Volume group and 1 huge drive so most of the docs on  
> LVM
> I've seen don't jive. Here's my pvdisplay:
>   --- Physical volume ---
>  PV Name               /dev/sda2
>  VG Name               VolGroup00
>  PV Size               148.91 GB / not usable 4.15 MB
>  Allocatable           yes (but full)
>  PE Size (KByte)       32768
>  Total PE              4765
>  Free PE               0
>  Allocated PE          4765
>  PV UUID               DOv3Cl-LWoU-JG04-PT0P-VfIV-89p2-yrdnbp
>
>  --- Physical volume ---
>  PV Name               /dev/sdb1
>  VG Name               VolGroup00
>  PV Size               149.05 GB / not usable 17.13 MB
>  Allocatable           NO
>  PE Size (KByte)       32768
>  Total PE              4769
>  Free PE               0
>  Allocated PE          4769
>  PV UUID               LK017x-dWzY-KIGL-kfOr-687Z-DgEn-YMfOw5
>
> As you can see it seems like there's no room...but here's my df print:
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/mapper/VolGroup00-LogVol00
>                      288G  170G  104G  63% /
> /dev/sda1              99M   31M   64M  33% /boot
> tmpfs                 315M     0  315M   0% /dev/shm
> /dev/sdc1             230G  134G   85G  62% /ext_drive
>
> So I'm running out of room and wanting to move all data to my main  
> drive
> so I can replace the 2nd drive with a bigger one. When I try a  
> pvmove it
> states I have no room:
> pvmove -v /dev/sdb1
>    Finding volume group "VolGroup00"
>  No extents available for allocation
>
> So now I'm lost...how can I put all data on my 1st drive and unhook  
> the
> 2nd from LVM to replace it ? Any assistance is greatly appreciated.  
> I'm
> installing system-config-lvm hoping the GUI may help me as well.

  You have 170G of data spread throughout both disks and you want to  
move everything to the main disk which has only 148GB of capacity ?  
That doesn't add up.

  You can add this new bigger drive and stay with 3 drives then  
pvmove /dev/sdb1 onto it and remove it from the volume group.

-Giovanni