Increasing LVM Size on Linux
Increasing disk space on a Linux machine may become necessary due to growing storage requirements, data expansion, application needs, file system limitations, or performance considerations. Expanding storage ensures sufficient capacity, accommodates future changes or updates, and prevents potential issues or performance degradation.
For this example, we’ll be using a QEMU virtual machine, but the steps apply to most Debian-based systems.
Step 1 - Check current storage
First, check how much space is currently available using df -h:
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root@server:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 967M 0 967M 0% /dev
tmpfs 198M 564K 197M 1% /run
/dev/mapper/server--vg-root 6.1G 2.1G 3.7G 37% /
tmpfs 986M 0 986M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sda1 470M 87M 359M 20% /boot
/dev/mapper/server--vg-var 2.3G 2.2G 0 100% /var
/dev/mapper/server--vg-home 21G 72K 20G 1% /home
/dev/mapper/server--vg-tmp 467M 19K 438M 1% /tmp
tmpfs 198M 0 198M 0% /run/user/1001
Here, /var is at 100% usage.
Now list all available disks with fdisk -l:
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root@server:~# fdisk -l
Disk /dev/sda: 32 GiB, 34359738368 bytes, 67108864 sectors
Disk model: QEMU HARDDISK
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: 0x1dde1ea9
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 999423 997376 487M 83 Linux
/dev/sda2 1001470 67106815 66105346 31.5G 5 Extended
/dev/sda5 1001472 67106815 66105344 31.5G 8e Linux LVM
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: QEMU HARDDISK
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/server--vg-root: 6.23 GiB, 6685720576 bytes, 13058048 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
Disk /dev/mapper/server--vg-var: 2.38 GiB, 2558525440 bytes, 4997120 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
Disk /dev/mapper/server--vg-swap_1: 976 MiB, 1023410176 bytes, 1998848 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
Disk /dev/mapper/server--vg-tmp: 492 MiB, 515899392 bytes, 1007616 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
Disk /dev/mapper/server--vg-home: 21.43 GiB, 23005757440 bytes, 44933120 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
This shows the existing 32 GB disk (/dev/sda) and the new 100 GB disk (/dev/sdb) that was added to the machine.
Step 2 - Partitioning the new disk
Since /dev/sdb has no partitions, we’ll create one using fdisk /dev/sdb:
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root@server:~# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.36.1).
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 0x0fbdf1f1.
In this case we are creating a partition while leaving everything as default: n p enter enter enter wq
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Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-209715199, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-209715199, default 209715199):
Created a new partition 1 of type 'Linux' and of size 100 GiB.
To see the new partition you can type p:
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Command (m for help): p
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: QEMU HARDDISK
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: 0x0fbdf1f1
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 209715199 209713152 100G 83 Linux
If everything is ready go ahead and write the partition and quit fdisk:
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Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
You should now see the new partition /dev/sdb1 if you run fdisk -l again:
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Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 209715199 209713152 100G 83 Linux
Now let’s create a new physical device with the newly partitioned disk using pvcreate:
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pvcreate /dev/sdb1
Output:
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Physical volume "/dev/sdb1" successfully created
To display just run:
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pvdisplay
Output:
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--- Physical volume ---
PV Name /dev/sda5
VG Name server-vg
PV Size 31.52 GiB / not usable 2.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 8069
Free PE 13
Allocated PE 8056
PV UUID FdNY35-hfqY-JG3g-B0D3-Yeld-wMRT-9K7UcE
"/dev/sdb1" is a new physical volume of "<100.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size <100.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID qZbxlj-fScv-IjAC-RWj9-Cisw-LD8t-2TTTEx
Step 3 - Check current volume group
Thereafter, let’s go ahead and check the current volume groups using vgdisplay:
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root@server:~# vgdisplay
--- Volume group ---
VG Name server-vg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 6
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 5
Open LV 5
Max PV 0
Cur PV 1
Act PV 1
VG Size <31.52 GiB
PE Size 4.00 MiB
Total PE 8069
Alloc PE / Size 8056 / <31.47 GiB
Free PE / Size 13 / 52.00 MiB
VG UUID gWgysA-P62Y-BD3x-Mw1V-MeqU-oX40-LdM4JB
Step 4 - Extend the current volume group.
Now we can extend it using vgextend and verify it using vgdisplay:
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root@server:~# vgextend ubuntu1604-vg /dev/sdb1
Volume group "server-vg" successfully extended
root@server:~# vgdisplay
--- Volume group ---
VG Name server-vg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 7
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 5
Open LV 5
Max PV 0
Cur PV 2
Act PV 2
VG Size <131.52 GiB
PE Size 4.00 MiB
Total PE 33668
Alloc PE / Size 8056 / <31.47 GiB
Free PE / Size 25612 / <100.05 GiB
VG UUID gWgysA-P62Y-BD3x-Mw1V-MeqU-oX40-LdM4JB
After that, let’s go ahead and check the logical volumes using lvdisplay:
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root@server:~# lvdisplay
---- Logical volume ---
LV Path /dev/server-vg/root
LV Name root
VG Name server-vg
LV UUID QBdSa5-Ol5p-0511-5dzY-7Erh-ZvxD-e4rPFl
LV Write Access read/write
LV Creation host, time server, 2023-04-04 10:55:57 +0100
LV Status available
# open 1
LV Size <6.23 GiB
Current LE 1594
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:0
--- Logical volume ---
LV Path /dev/server-vg/var
LV Name var
VG Name server-vg
LV UUID E14kW7-dnny-7q1g-1wmu-EAMR-lkBs-psWmX8
LV Write Access read/write
LV Creation host, time server, 2023-04-04 10:55:58 +0100
LV Status available
# open 1
LV Size 2.38 GiB
Current LE 610
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:1
--- Logical volume ---
LV Path /dev/server-vg/swap_1
LV Name swap_1
VG Name server-vg
LV UUID 3M776F-gHjB-QR9C-21TM-Dill-sszf-5gjyCa
LV Write Access read/write
LV Creation host, time server, 2023-04-04 10:55:58 +0100
LV Status available
# open 2
LV Size 976.00 MiB
Current LE 244
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:2
--- Logical volume ---
LV Path /dev/server-vg/tmp
LV Name tmp
VG Name server-vg
LV UUID Bc9VLb-inLP-Og1w-K27B-K5EZ-1jYu-HBufBB
LV Write Access read/write
LV Creation host, time server, 2023-04-04 10:55:58 +0100
LV Status available
# open 1
LV Size 492.00 MiB
Current LE 123
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:3
--- Logical volume ---
LV Path /dev/server-vg/home
LV Name home
VG Name server-vg
LV UUID um1BeP-GMLx-Ry3F-8KB1-psKU-37zW-9e82VJ
LV Write Access read/write
LV Creation host, time server, 2023-04-04 10:55:58 +0100
LV Status available
# open 1
LV Size <21.43 GiB
Current LE 5485
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:4
Step 5 - Extend the volume.
In our case we are extending var volume by 32 GiB using lvextend:
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root@server:~# lvextend --resizefs -L+32G /dev/server-vg/var
Size of logical volume server-vg/var changed from 2.38 GiB (610 extents) to 34.38 GiB (8802 extents).
Logical volume server-vg/var successfully resized.
resize2fs 1.46.2 (28-Feb-2021)
Filesystem at /dev/mapper/server--vg-var is mounted on /var; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 5
The filesystem on /dev/mapper/server--vg-var is now 9013248 (4k) blocks long.
Step 6 - Allocate entire disk space to the volume
You can assign a percentage of the disk with the following command:
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root@server:~# lvextend --resizefs -l +100%FREE /dev/server-vg/var
Step 7 - Final Check
Verify the expansion worked with df -h. The /var partition should now reflect the new size.
Conclusion
Expanding LVM storage in Linux is a straightforward process once you understand the workflow: add a new disk → create a physical volume → extend the volume group → resize the logical volume and filesystem. This flexibility is one of the main advantages of using LVM, as it allows you to scale storage dynamically without downtime or complex migrations.
By following the steps above, you can ensure your system adapts to growing storage needs and keeps running smoothly.
Source: Harry Vasanth
Originally posted under the licence CC BY 4.0.