Resize the primary disk (suggested)¶
If you need to resize the primary disk, you will need to grow your partition on the disk and then tell LVM to recognise the new space.
.. warning::
Please be aware that this article uses specific examples, such as :code:`sdc` or :code:`/dev/mapper/eCloud-root`.
You may have different requirements or configurations in terms of device names and volumes.
Performing this incorrectly may make irreversible changes to your filesystem or cause data loss, so please proceed with care and caution.
Once an extension has been started, it cannot be reverted.
**This article is for those comfortable with Linux administration.** If you're not comfortable with Linux and want to increase the amount of disk space assigned to your server, UKFast customers may raise a support ticket.
Resize the disk in MyUKFast¶
You may start off with a VM like so:
[root@ssh ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 15G 0 disk
├─sda1 8:1 0 512M 0 part /boot
└─sda2 8:2 0 14.5G 0 part
├─eCloud-root 253:0 0 13.5G 0 lvm /
└─eCloud-swap 253:1 0 1G 0 lvm [SWAP]
In this example, we can see that the disk /dev/sda is 15G in size.
The first step from here is to resize the disk in the MyUKFast portal. This can be done by visiting:
MyUKFast -> eCloud -> Public/Private/Hybrid -> [Click the server]
Rescan the SCSI hosts¶
Following this, we need to rescan the SCSI hosts to detect changes in disk size.
[root@ssh ~]# for i in /sys/class/scsi_host/host*/scan; do echo "- - -" > $i; done
[root@ssh ~]# for i in /sys/class/scsi_device/*/device/rescan; do echo "1" > $i; done
Extend an existing partition¶
Once the disk has been extended using the eCloud control panel, you will use the growpart command to extend the last partition.
In the below example we can see that the last device partition number is /dev/sda2
Note now how the size of /dev/sda is now 20G whereas previously this was 15G
[root@id116041 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 512M 0 part /boot
└─sda2 8:2 0 14.5G 0 part
├─eCloud-root 253:0 0 13.5G 0 lvm /
└─eCloud-swap 253:1 0 1G 0 lvm [SWAP]
We can see in this example that our LVM drive is on /dev/sda2 so this is the partition that we need to expand.
Now that we have the partition number that we are going to extend, we will use the following command to grow the size of the last partition
[root@ssh ~]# growpart /dev/sda 2
CHANGED: partition=2 start=1050624 old: size=30406623 end=31457247 new: size=40892383 end=41943007
Going back to lsblk we can now see the size of the partition has now also changed to around 20G:
[root@ssh ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 512M 0 part /boot
└─sda2 8:2 0 19.5G 0 part
├─eCloud-root 253:0 0 13.5G 0 lvm /
└─eCloud-swap 253:1 0 1G 0 lvm [SWAP]
Now we need to resize the physical volume into the newly extended disk and confirm that this is correct in pvs
[root@ssh ~]# pvresize /dev/sda2
Physical volume "/dev/sda2" changed
1 physical volume(s) resized or updated / 0 physical volume(s) not resized
[root@ssh ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 eCloud lvm2 a-- <19.50g 5.00g
Extending the logical volume onto the increased volume group¶
.. note::
If you want to create a new partition from this disk (to have :code:`/` and :code:`/home` on separate partitions, for example) you would need to create a new Logical Volume instead of extending the existing one.
This should only be performed by advanced users when absolutely required.
For most use cases, a large :code:`/` partition will be all that is needed.
As we've resized an underlying disk, you can only extend or create new volumes in the Volume Group with free space.
In this instance, we’ll be doing the most common extension of /. Note the path in this command is /dev/mapper/VG-LV from the table above:
[root@ssh ~]# lvresize -l +100%FREE /dev/mapper/eCloud-root
Size of logical volume eCloud/root changed from <13.50 GiB (3455 extents) to <18.50 GiB (4735 extents).
Logical volume eCloud/root successfully resized.
[root@ssh ~]#
Confirm that this has resized the logical volume (LV) as expected:
root@ssh ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root eCloud -wi-ao---- <18.50g
swap eCloud -wi-ao---- 1.00g
[root@ssh ~]#
Resize the filesystem to make the new space available¶
Now that the disk and LV show the correct sizes, we can go ahead and resize the filesystem. Some servers use the ext filesystem type, and others user xfs. To identify which yours uses, run the following:
[root@ssh ~]# df -T
Filesystem Type 1K-blocks Used Available Use% Mounted on
[...]
/dev/mapper/eCloud-root ext4 13800600 1378772 11776020 11% /
[root@ssh ~]#
In this example, the server is using ext4.
Resizing EXT4 filesystems¶
To resize an ext4 filesystem, run the following, noting the /dev/mapper/VG-LV format of on the device name:
[root@ssh ~]# resize2fs /dev/mapper/eCloud-root
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/mapper/eCloud-root is mounted on /; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 3
The filesystem on /dev/mapper/eCloud-root is now 4848640 blocks long.
Resizing XFS filesystems¶
To resize an xfs filesystem, run the following, noting the /dev/mapper/VG-LV format of on the device name:
[root@ssh ~]# xfs_growfs /dev/mapper/eCloud-root