This article shows how to expand a filesystem on a CentOS 7 or Redhat Enterprise Linux 7 system by adding a second disk/filesystem.
The disk in this example is “/dev/sda” and it has two filesystems on it “/dev/sda1” and “/dev/sda2”. There is plenty of unused disk space available no “/dev/sda”. We’ll be extending the “/root” filesystem.
Add a partition using all available (previously unused) disk space. Make sure to create your partition as type “8e”.
fdisk /dev/sda
Run “partprobe” to make sure the kernel knows about the new partition.
partprobe
Get the Volume Group name which has “/root”:
vgdisplay
Add the new partition/disk to this Volume Group:
vgextend centos /dev/sda3
RUn PV Scan:
pvscan
You’ll see something like the following where the new partition/filesystem is available in the right Volume Group:
PV /dev/sda2 VG centos lvm2 [9.51 GiB / 40.00 MiB free] PV /dev/sda3 VG centos lvm2 [90.00 GiB / 90.00 GiB free]
Extend the filesystem over the new partition/filesystem:
lvextend /dev/centos/root /dev/sda3 xfs_growfs -d /dev/centos/root
Check your work:
df -h