Centos 7 Extend partition with unallocated space

Question

I have centos 7 server (CentOS Linux release 7.3.1611 (Core)) When I was updated my server I saw error you need extra space. But I had 20GB disk on server when I check disk spaces I saw only 4.5GB partition created and 16GB partition is free space no unallocated. How I can extend partition from 16GB free space?

lsblk:

NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
fd0               2:0    1    4K  0 disk
sda               8:0    0   20G  0 disk
├─sda1            8:1    0  500M  0 part /boot
└─sda2            8:2    0  4.5G  0 part
  ├─centos-root 253:0    0    4G  0 lvm  /
  └─centos-swap 253:1    0  512M  0 lvm  [SWAP]
sr0              11:0    1 1024M  0 rom

do `man lvm` or http://tldp.org/HOWTO/LVM-HOWTO/ – alexus Jul 11 '17 at 13:16 — alexus, Jul 11 '17 at 13:16

score 43 · Answer 1 · answered Feb 12 '19 at 23:20

You can do this without rebooting in CentOS 7. Assuming your disk is /dev/vda and standard RHEL/CentOS partitioning:

Extend partition

# fdisk /dev/vda

Enter p to print your initial partition table.

Enter d (delete) followed by 2 to delete the existing partition definition (partition 1 is usually /boot and partition 2 is usually the root partition).

Enter n (new) followed by p (primary) followed by 2 to re-create partition number 2 and enter to accept the start block and enter again to accept the end block which is defaulted to the end of the disk.

Enter t (type) then 2 then 8e to change the new partition type to "Linux LVM".

Enter p to print your new partition table and make sure the start block matches what was in the initial partition table printed above.

Enter w to write the partition table to disk. You will see an error about Device or resource busy which you can ignore.

Update kernel in-memory partition table

After changing your partition table, run the following command to update the kernel in-memory partition table:

# partx -u /dev/vda

Resize physical volume

Resize the PV to recognize the extra space

# pvresize /dev/vda2

Resize LV and filesystem

In this command centos is the PV, root is the LV and /dev/vda2 is the partition that was extended. Use pvs and lvs commands to see your physical and logical volume names if you don't know them. The -r option in this command resizes the filesystem appropriately so you don't have to call resize2fs or xfs_growfs separately.

# lvextend -r centos/root /dev/vda2

This is brilliant. Thank you! This should be the accepted answer. I was missing the last step to resize the lv and file system! — Skinner927, Jan 31 '20 at 20:39
Also thank you, it worked. For other readers, I got asked an extra question by fdisk while executing the above (centos 7.8), I answered with No, and it worked: Partition #5 contains a LVM2_member signature. Do you want to remove the signature? [Y]es/[N]o: n — ionescu77, Oct 19 '20 at 14:53

score 33 · Accepted Answer · answered Jul 11 '17 at 13:52

33

There are three steps to make:

alter your partition table so sda2 ends at end of disk
reread the partition table (will require a reboot)
resize your LVM pv using pvresize

Step 1 - Partition table

Run fdisk /dev/sda. Issue p to print your current partition table and copy that output to some safe place. Now issue d followed by 2 to remove the second partition. Issue n to create a new second partition. Make sure the start equals the start of the partition table you printed earlier. Make sure the end is at the end of the disk (usually the default).

Issue t followed by 2 followed by 8e to toggle the partition type of your new second partition to 8e (Linux LVM).

Issue p to review your new partition layout and make sure the start of the new second partition is exactly where the old second partition was.

If everything looks right, issue w to write the partition table to disk. You will get an error message from partprobe that the partition table couldn't be reread (because the disk is in use).

Reboot your system

This step is neccessary so the partition table gets re-read.

Resize the LVM PV

After your system rebooted invoke pvresize /dev/sda2. Your Physical LVM volume will now span the rest of the drive and you can create or extend logical volumes into that space.

answered Jul 11 '17 at 13:52

Andreas Rogge

2,670
10
24

a great solution, it works perfectly. still only the part how to extend logical volumes. – Mimouni Mar 12 '18 at 15:00
9

This excelent answer stopped just short of the finish line! I figured out how to finish it off. The example shared in the question showed two logical volumes underneith `sda2`: `centos-root` and `centos-swap`. In this case, the volume group is `centos` and the two logical volumes inside that group are `root` and `swap`. If we wanted to extend the `centos-root` volume in this example with 50% of the available space in our freshly-extended `sda2` partition, we would use `lvextend -r -l +50%FREE /dev/centos/root`. The `-r` resizes the underlying file system to match the extended logical volume. – Shadoninja Jul 01 '19 at 18:25
@Shadoninja that's out of scope of the original question. So I didn't add it and will not add it to this question in the future. – Andreas Rogge Jul 03 '19 at 15:36
2

@AndreasRogge I would argue that is entirely within the scope of this question as the terminology in this space can be confusing and easy to conflate. It is worth posting a complete summary of how to get unallocated disk space usable by the file system since that will be an extremely common reason for people to find this question. – Shadoninja Jul 09 '19 at 17:36
1

This solution didn't work for me: ` pvresize /dev/sda2 Failed to find physical volume "/dev/sda2". 0 physical volume(s) resized or updated / 0 physical volume(s) not resized` – Alex G May 27 '20 at 14:59
1

I used this command on my centos box with 2 partitions: sudo lvextend -v -r -l +100%FREE /dev/centos/root. -v will give a great verbose output. – user674669 Jun 18 '20 at 18:31
I agree with @Shadoninja, as extending a logical volume after extending the partition is what many intend to do as a use case. It's also what brought me here. – TheKarateKid Sep 26 '20 at 06:23
1

@TheKarateKid I'll happily answer another question concerning resizing the LV itself. However, it is usually not that simple and you need to resize the filesystem, too which is filesystem-specific again. If someone finds a question that describes how to resize the LV itself, I will happily link it in my answer. Also, I would include the `partx` that @Aner suggested in his answer. – Andreas Rogge Sep 27 '20 at 09:35
@AlexG I had the same problem. It seems (from `pvdisplay`, as well as `lvdisplay`) that I don't have any volumes. but that was not a problem, I've just ommited this step and the disk space is increased - I just had to increase the filesystem with `xfs_growfs` – Line Jun 16 '21 at 08:53

score 11 · Answer 3 · edited Oct 06 '20 at 18:14

Check this out — everything on a single line, no questions:

parted ---pretend-input-tty /dev/vda resizepart 2 100%;
partx -u /dev/vda; pvresize /dev/vda2;
lvextend -r centos/var /dev/vda2

Here:

parted extends partition (---pretend-input-tty is a hidden parted flag)
partx updates kernel in-memory partition table
pvresize resizes physical volume
lvextend resizes logical volume and filesystem

This way reboot is not needed.

The above implies that you have vd* volumes, and under vda2 there is an lvm volume group centos and lvm logical volume var:

$ lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
fd0               2:0    1    4K  0 disk 
vda               8:0    0   40G  0 disk 
├─vda1            8:1    0    1G  0 part /boot
└─vda2            8:2    0   19G  0 part 
  ├─centos-var  253:0    0   17G  0 lvm  /
  └─centos-swap 253:1    0    2G  0 lvm  [SWAP]
sr0              11:0    1 1024M  0 rom

If you have sd* volumes, like here:

$ lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
fd0           2:0    1    4K  0 disk 
sda           8:0    0   40G  0 disk 
├─sda1        8:1    0    1G  0 part /boot
└─sda2        8:2    0   19G  0 part 
  ├─cl-root 253:0    0   17G  0 lvm  /
  └─cl-swap 253:1    0    2G  0 lvm  [SWAP]
sr0          11:0    1 1024M  0 rom

You can do it the same way:

parted ---pretend-input-tty /dev/sda resizepart 2 100%;
partx -u /dev/sda; pvresize /dev/sda2;
lvextend -r /dev/cl/root /dev/sda2

You should consider adding explanations and your environment. For instance, my partx doesn't have option `-u` (Centos6.7 util-linux-ng-2.17.2-12.28.el6). — Boop, Aug 19 '19 at 09:40
this command worked perfect for me. in my case I used ```centos/root``` instead of ```centos/var``` — Muthukumar Anbalagan, Feb 01 '22 at 09:01

liwt31 · Answer 4 · 2018-11-24T11:09:14.493

For those who're having trouble extending logical volumes like me, reading this post might be helping. In summary, you can use lvextend to extend your logical volume: lvextend -l +<PE> <LV_PATH> you can obtain the number of remaining PE(<PE>) by vgdisplay and obtain the path of your logical volume(LV_PATH) by lvdisplay.

Then depending on your distribution, you either want xfs_growfs <LV_PATH> (Centos 7) or resize2fs <LV_PATH> to finally resize.

score 0 · Answer 5 · answered Feb 09 '22 at 16:46

0

How can I do the same thing but with the example below. https://prnt.sc/26s9s0w https://prnt.sc/26s9uou

answered Feb 09 '22 at 16:46

Alex Hardy

1

If you have a new question, please ask it by clicking the [Ask Question](https://serverfault.com/questions/ask) button. Include a link to this question if it helps provide context. - [From Review](/review/late-answers/511864) – Dave M Feb 14 '22 at 16:14