4.2. Creating LVM logical volume

Procédure

1. Create a logical volume:

   # lvcreate -n mylv -L 500M myvg

   Use the -n option to set the LV name to mylv, and the -L option to set the size of LV in units of Mb, but it is possible to use any other units. The LV type is linear by default, but the user can specify the desired type by using the --type option.

   Important

   The command fails if the VG does not have a sufficient number of free physical extents for the requested size and type.

2. View the created logical volumes by using any one of the following commands as per your requirement:

   1. The lvs command provides logical volume information in a configurable form, displaying one line per logical volume:

      # lvs
        LV   VG   Attr         LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
       mylv myvg -wi-ao----   500.00m

   2. The lvdisplay command displays logical volume properties, such as size, layout, and mapping in a fixed format:

      # lvdisplay -v /dev/myvg/mylv
        --- Logical volume ---
        LV Path                /dev/myvg/mylv
        LV Name                mylv
        VG Name                myvg
        LV UUID                YTnAk6-kMlT-c4pG-HBFZ-Bx7t-ePMk-7YjhaM
        LV Write Access        read/write
      [..]

   3. The lvscan command scans for all logical volumes in the system and lists them:

      # lvscan
       ACTIVE                   '/dev/myvg/mylv' [500.00 MiB] inherit

3. Create a file system on the logical volume. The following command creates an xfs file system on the logical volume:

   # mkfs.xfs /dev/myvg/mylv
   meta-data=/dev/myvg/mylv       isize=512    agcount=4, agsize=32000 blks
            =                       sectsz=512   attr=2, projid32bit=1
            =                       crc=1        finobt=1, sparse=1, rmapbt=0
            =                       reflink=1
   data     =                       bsize=4096   blocks=128000, imaxpct=25
            =                       sunit=0      swidth=0 blks
   naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
   log      =internal log           bsize=4096   blocks=1368, version=2
            =                       sectsz=512   sunit=0 blks, lazy-count=1
   realtime =none                   extsz=4096   blocks=0, rtextents=0
   Discarding blocks...Done.

4. Mount the logical volume and report the file system disk space usage:

   # mount /dev/myvg/mylv /mnt
   
   # df -h
   Filesystem               1K-blocks  Used   Available Use% Mounted on
   
   /dev/mapper/myvg-mylv   506528    29388  477140     6%   /mnt