Resize LVM on UCS

Note: There is a video available for this article.

If you run out of space on a partition you have to clean up or you can add more space, like an additional harddisk, additional volume in a virtual environment or resize the virtual image.

In all cases the new disk needs to be integrated.

  1. You can partition the new disk and mount it to a new folder
    This is not described here!
  2. You can resize the logical volume (LV). LV is part of the UCS partitioning by default.
    How to do this is now described in this article

First you can get an overview of the physical volume (PV), the volume groups (VG) and logical volumes (LV) of the installation.

root@master:~# pvs
  PV         VG     Fmt  Attr PSize PFree
  /dev/sda5  vg_ucs lvm2 a--  9,52g    0·
root@master:~# vgs
  VG     #PV #LV #SN Attr   VSize VFree
  vg_ucs   1   2   0 wz--n- 9,52g    0·
root@master:~# lvs
  LV     VG     Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root   vg_ucs -wi-ao----   9,10g
  swap_1 vg_ucs -wi-ao---- 432,00m

Now, if you have already add a new disk, you can find it via

root@master:~# lsblk
  sdb                 8:16   0    5G  0 disk  
  sr0                11:0    1 1024M  0 rom  
  sda                 8:0    0   10G  0 disk 
  ├─sda2              8:2    0    1K  0 part 
  ├─sda5              8:5    0  9,5G  0 part 
  │ ├─vg_ucs-swap_1 254:1    0  432M  0 lvm  [SWAP]
  │ └─vg_ucs-root   254:0    0  9,1G  0 lvm  /
  └─sda1              8:1    0  487M  0 part /boot

The disk has already to be partitioned. You can use cfdisk if you like

root@master:~# cfdisk /dev/sdb

First you get a short selection menu:

Select label type
  │ gpt  
  │ dos  
  │ sgi   
  │ sun 

Please choose gpt and then make a new partition with your desired size. Close cfdisk writting the changes to disk first and then quit.
After that you want to create a new physikal volume on the new partition.

root@master:~# pvcreate /dev/sdb1
  Physical volume "/dev/sdb1" successfully created
root@master:~# pvs
  PV         VG     Fmt  Attr PSize PFree
  /dev/sda5  vg_ucs lvm2 a--  9,52g    0·
  /dev/sdb1         lvm2 ---  5,00g 5,00g

To increase at least the LV “root” the VG has to be increased first.

root@master:~# vgextend vg_ucs /dev/sdb1
  Volume group "vg_ucs" successfully extended
root@master:~# vgs
  VG     #PV #LV #SN Attr   VSize  VFree
  vg_ucs   2   2   0 wz--n- 14,52g 5,00g

Finally, in this case, the LV “root” can be resized. You can expand “root” with the whole new space like this:

root@master:~# lvextend -l +100%FREE /dev/mapper/vg_ucs-root
   Size of logical volume vg_ucs/root changed from 9,10 GiB (2329 extents) to 14,09 GiB (3608 extents).
   Logical volume root successfully resized

To update the changes

root@master:~# resize2fs -p /dev/mapper/vg_ucs-root
  resize2fs 1.42.12 (29-Aug-2014)
  Filesystem at /dev/mapper/vg_ucs-root is mounted on / ;on-line resizing required
  old_desc_blocks = 1, new_desc_blocks = 1
  The filesystem on /dev/mapper/vg_ucs-root is now 3694592 (4k) blocks long.
root@master:~# df -h
  Dateisystem    Größe Benutzt Verf. Verw% Eingehängt auf
  udev             10M       0   10M    0% /dev
  tmpfs           401M     13M  389M    4% /run
  /dev/dm-0        14G    2,2G   11G   17% /
  tmpfs          1003M       0 1003M    0% /dev/shm
  tmpfs           5,0M       0  5,0M    0% /run/lock
  tmpfs          1003M       0 1003M    0% /sys/fs/cgroup
  /dev/sda1       472M     97M  351M   22% /boot
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