How to setup Logical Volume Manager on a VM.
Install LVM.
yum install lvm2 |
Check the disks available. We are going to run LVM on /dev/sdb.
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 20G 0 disk ├─sda1 8:1 0 200M 0 part /boot/efi └─sda2 8:2 0 19.8G 0 part / sdb 8:16 0 20G 0 disk |
Create a physical volume on /dev/sdb.
$ pvcreate /dev/sdb Physical volume "/dev/sdb" successfully created. $ pvs PV VG Fmt Attr PSize PFree /dev/sdb vg lvm2 a-- <20.00g 0 |
Create a volume group called vg.
$ vgcreate vg /dev/sdb Volume group "vg" successfully created $ vgs VG #PV #LV #SN Attr VSize VFree vg 1 0 0 wz--n- <20.00g <20.00g |
Create a 10GB logical volume group called data.
$ lvcreate -L 10G -n data vg Logical volume "data" created. $ lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert data vg -wi-a----- 10.00g |
Format the volume group and mount it.
$ mkfs.xfs /dev/vg/data meta-data=/dev/vg/data isize=512 agcount=4, agsize=655360 blks = sectsz=4096 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=1 data = bsize=4096 blocks=2621440, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=2560, version=2 = sectsz=4096 sunit=1 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 Discarding blocks...Done. $ mount /dev/vg/data /mnt |
Check your logical volume. It says 10GB.
$ df -Th Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 385M 0 385M 0% /dev tmpfs tmpfs 403M 0 403M 0% /dev/shm tmpfs tmpfs 403M 5.5M 398M 2% /run tmpfs tmpfs 403M 0 403M 0% /sys/fs/cgroup /dev/sda2 xfs 20G 2.9G 17G 15% / /dev/sda1 vfat 200M 5.8M 195M 3% /boot/efi tmpfs tmpfs 81M 0 81M 0% /run/user/1000 /dev/mapper/vg-data xfs 10G 104M 9.9G 2% /mnt |
Let’s now extend the logical volume to 20GB.
$ lvextend -l +100%FREE /dev/vg/data Size of logical volume vg/data changed from 10.00 GiB (2560 extents) to <20.00 GiB (5119 extents). Logical volume vg/data successfully resized. |
Although lsblk says 20GB, our logical volume still says 10GB.
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 20G 0 disk ├─sda1 8:1 0 200M 0 part /boot/efi └─sda2 8:2 0 19.8G 0 part / sdb 8:16 0 20G 0 disk └─vg-data 253:0 0 20G 0 lvm /mnt $ df -Th Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 385M 0 385M 0% /dev tmpfs tmpfs 403M 0 403M 0% /dev/shm tmpfs tmpfs 403M 5.5M 398M 2% /run tmpfs tmpfs 403M 0 403M 0% /sys/fs/cgroup /dev/sda2 xfs 20G 2.9G 17G 15% / /dev/sda1 vfat 200M 5.8M 195M 3% /boot/efi tmpfs tmpfs 81M 0 81M 0% /run/user/1000 /dev/mapper/vg-data xfs 10G 104M 9.9G 2% /mnt |
We need to grow the file system.
$ xfs_growfs /dev/vg/data meta-data=/dev/mapper/vg-data isize=512 agcount=4, agsize=655360 blks = sectsz=4096 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=1 data = bsize=4096 blocks=2621440, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=2560, version=2 = sectsz=4096 sunit=1 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 data blocks changed from 2621440 to 5241856 |
Let’s check again.
$ df -Th Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 385M 0 385M 0% /dev tmpfs tmpfs 403M 0 403M 0% /dev/shm tmpfs tmpfs 403M 5.5M 398M 2% /run tmpfs tmpfs 403M 0 403M 0% /sys/fs/cgroup /dev/sda2 xfs 20G 2.9G 17G 15% / /dev/sda1 vfat 200M 5.8M 195M 3% /boot/efi tmpfs tmpfs 81M 0 81M 0% /run/user/1000 /dev/mapper/vg-data xfs 20G 176M 20G 1% /mnt |
It now says 20GB.