How to extend a LVM Volume-Group
A Volume Group of an LVM can be enlarged by additional hard disks/SSD/NVMe at any time.
WARNING
Before you do any changes, make a backup and keep it handy!
Environment in this how-to:
- Disk already in use:
/dev/vda - New Disk to be used:
/dev/sda - System-Version:
UCS 4.4-7
Step 1: Format Storage-Device
First you need to know which device you want to format. In my case it is /dev/sda:
root@schuldc2-5:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 12G 0 disk
vda 254:0 0 50G 0 disk
├─vda1 254:1 0 487M 0 part /boot
├─vda2 254:2 0 1K 0 part
└─vda5 254:5 0 49,5G 0 part
├─vg_ucs-root 253:0 0 47,5G 0 lvm /
└─vg_ucs-swap_1 253:1 0 2G 0 lvm [SWAP]
Then format it using fdisk:
root@schuldc2-5:~# fdisk /dev/sda
Welcome to fdisk (util-linux 2.29.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xc4a9dbf5.
Command (m for help): n # n for new
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p # we want to create a primary partition, so p
Partition number (1-4, default 1): 1 # use default value
First sector (2048-25165823, default 2048): # use default value
Last sector, +sectors or +size{K,M,G,T,P} (2048-25165823, default 25165823): # use default value
Created a new partition 1 of type 'Linux' and of size 12 GiB.
Command (m for help): t # t for table
Selected partition 1 # partition-number, previously used
Partition type (type L to list all types): 8e # 8e for LVM-Partition-Type
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): w # write changes to disk
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
With fdisk -l, you can check if formatting worked.
root@schuldc2-5:~# fdisk -l /dev/sda
Disk /dev/sda: 12 GiB, 12884901888 bytes, 25165824 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc4a9dbf5
Device Boot Start End Sectors Size Id Type
/dev/sda1 2048 25165823 25163776 12G 8e Linux LVM
Step 2: Initializing the New Partition as a Physical Volume (pv)
Now you need to setup the new Disk as Physical Volume
root@schuldc2-5:~# pvcreate /dev/sda1
Physical volume "/dev/sda1" successfully created.
Step 3: Extend your Volume Group (vg) with the new pv
root@schuldc2-5:~# vgextend vg_ucs /dev/sda1
Volume group "vg_ucs" successfully extended
You can see if it worked with the pvscan command:
root@schuldc2-5:~# pvscan
PV /dev/vda5 VG vg_ucs lvm2 [49,52 GiB / 0 free]
PV /dev/sda1 VG vg_ucs lvm2 [12,00 GiB / 12,00 GiB free]
Total: 2 [61,52 GiB] / in use: 2 [61,52 GiB] / in no VG: 0 [0 ]
Step 4: Extend your Logical Volume (lv)
root@schuldc2-5:~# lvextend -l +100%FREE /dev/vg_ucs/root
Size of logical volume vg_ucs/root changed from 47,52 GiB (12165 extents) to 59,52 GiB (15236 extents).
Logical volume vg_ucs/root successfully resized.
Step 5: Resize your filesystem so it uses all of the new free space
root@schuldc2-5:~# resize2fs /dev/mapper/vg_ucs-root
resize2fs 1.43.4 (31-Jan-2017)
Dateisystem bei /dev/mapper/vg_ucs-root ist auf / eingehängt; Online-Größenänderung ist
erforderlich
old_desc_blocks = 6, new_desc_blocks = 8
Das Dateisystem auf /dev/mapper/vg_ucs-root is nun 15601664 (4k) Blöcke lang.
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