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”.
Run “partprobe” to make sure the kernel knows about the new partition.
Get the Volume Group name which has “/root”:
Add the new partition/disk to this Volume Group:
vgextend centos /dev/sda3
RUn PV Scan:
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: