Home / ubuntu / Questions / 1314461
Accepted
D.Zou
Asked: 2021-02-08 11:32:45 +0800 CST

LVM instructions confuses me

  • 772

I have ubuntu 20 server installed and during the installation it asked me if I want to use LVM and I did. Now I am trying to mount the LVM but I am getting confused on what to do.

$ sudo lvmdiskscan
  /dev/loop0 [      69.88 MiB] 
  /dev/loop1 [      55.38 MiB] 
  /dev/loop2 [     <31.09 MiB] 
  /dev/sda2  [       1.00 GiB] 
  /dev/loop3 [      55.46 MiB] 
  /dev/sda3  [      <1.64 TiB] LVM physical volume
  0 disks
  5 partitions
  0 LVM physical volume whole disks
  1 LVM physical volume
$ df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               7.8G     0  7.8G   0% /dev
tmpfs                              1.6G  1.7M  1.6G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  196G  6.2G  180G   4% /
tmpfs                              7.9G     0  7.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/sda2                          976M  104M  806M  12% /boot
/dev/loop0                          70M   70M     0 100% /snap/lxd/19188
/dev/loop2                          32M   32M     0 100% /snap/snapd/10707
/dev/loop1                          56M   56M     0 100% /snap/core18/1944
/dev/loop3                          56M   56M     0 100% /snap/core18/1988
tmpfs                              1.6G     0  1.6G   0% /run/user/1000
$ sudo pvscan
  PV /dev/sda3   VG ubuntu-vg       lvm2 [<1.64 TiB / 1.44 TiB free]
  Total: 1 [<1.64 TiB] / in use: 1 [<1.64 TiB] / in no VG: 0 [0   ]
$ sudo vgscan
  Found volume group "ubuntu-vg" using metadata type lvm2
$ sudo vgchange -ay 
  1 logical volume(s) in volume group "ubuntu-vg" now active
$ sudo lvscan 
  ACTIVE            '/dev/ubuntu-vg/ubuntu-lv' [200.00 GiB] inherit
$ sudo vgdisplay
  --- Volume group ---
  VG Name               ubuntu-vg
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <1.64 TiB
  PE Size               4.00 MiB
  Total PE              428848
  Alloc PE / Size       51200 / 200.00 GiB
  Free  PE / Size       377648 / 1.44 TiB
  VG UUID               Qy1h42-pePJ-6P8L-kNjM-5bN4-kg88-oWL8lA

So as you can see I have /dev/sda3 physical volume. It is part of ubuntu-vg volume group. But when I look at the vgdisplay, I see the free PE of 1.44T. So I can make a new VG that uses those free space right?

My end goal is just to mount that extra space and using it as a movie storage device and mount it on /mnt/media and I am not sure how to proceed from there.

edit:

$ sudo lsblk
NAME                      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
loop0                       7:0    0 69.9M  1 loop /snap/lxd/19188
loop1                       7:1    0 55.4M  1 loop /snap/core18/1944
loop2                       7:2    0 31.1M  1 loop /snap/snapd/10707
loop3                       7:3    0 55.5M  1 loop /snap/core18/1988
sda                         8:0    0  1.7T  0 disk 
├─sda1                      8:1    0    1M  0 part 
├─sda2                      8:2    0    1G  0 part /boot
└─sda3                      8:3    0  1.7T  0 part 
  └─ubuntu--vg-ubuntu--lv 253:0    0  200G  0 lvm  /mnt/media
sr0                        11:0    1 1024M  0 rom
partitioning

1 Answers

  1. Best Answer

    You can add a new logical volume from that spare space but not a new volume group, because a VG would require its own PVs and your only PV is sda3.

    So to create a new 100GiB logical volume called my-new-lv:

    $ sudo lvcreate -L100g /dev/ubuntu-vg/my-new-lv

    To make use of it:

    $ sudo mkfs.ext4 /dev/ubuntu-vg/my-new-lv
$ sudo mkdir -p /mnt/media
$ sudo mount /dev/ubuntu-vg/my-new-lv /mnt/media

    Verify it's there and mounted:

    $ df -h /mnt/media

    Should show a roughly 100GiB filesystem mounted there.

    Don't forget to add it to /etc/fstab so that it gets mounted next time. Example line:

    /dev/ubuntu-vg/my-new-lv /mnt/media ext4 defaults,noatime 0 2
    • 1