For this recipe, the setup has three SCSI disks that will be put into a logical volume using LVM. The disks are at /dev/sda, /dev/sdb, and /dev/sdc.
Before you can use a disk in a volume group you will have to prepare it:
The following will destroy any data on /dev/sda, /dev/sdb, and /dev/sdc
Run pvcreate on the disks
# pvcreate /dev/sda # pvcreate /dev/sdb # pvcreate /dev/sdc
Create a volume group
# vgcreate my_volume_group /dev/sda /dev/sdb /dev/sdc/
Run vgdisplay to verify volume group
# vgdisplay # vgdisplay --- Volume Group --- VG Name my_volume_group VG Access read/write VG Status available/resizable VG # 1 MAX LV 256 Cur LV 0 Open LV 0 MAX LV Size 255.99 GB Max PV 256 Cur PV 3 Act PV 3 VG Size 1.45 GB PE Size 4 MB Total PE 372 Alloc PE / Size 0 / 0 Free PE / Size 372/ 1.45 GB VG UUID nP2PY5-5TOS-hLx0-FDu0-2a6N-f37x-0BME0Y
If the volume group looks correct, it is time to create a logical volume on top of the volume group.
You can make the logical volume any size you like. (It is similar to a partition on a non LVM setup.) For this example we will create just a single logical volume of size 1GB on the volume group. We will not use striping because it is not currently possible to add a disk to a stripe set after the logical volume is created.
# lvcreate -L1G -nmy_logical_volume my_volume_group lvcreate -- doing automatic backup of "my_volume_group" lvcreate -- logical volume "/dev/my_volume_group/my_logical_volume" successfully created
Create an ext2 file system on the logical volume
# mke2fs /dev/my_volume_group/my_logical_volume mke2fs 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09 Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 131072 inodes, 262144 blocks 13107 blocks (5.00%) reserved for the super user First data block=0 9 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376 Writing inode tables: done Writing superblocks and filesystem accounting information: done
Mount the logical volume and check to make sure everything looks correct
# mount /dev/my_volume_group/my_logical_volume /mnt # df Filesystem 1k-blocks Used Available Use% Mounted on /dev/hda1 1311552 628824 616104 51% / /dev/my_volume_group/my_logical_volume 1040132 20 987276 0% /mnt
If everything worked properly, you should now have a logical volume with and ext2 file system mounted at /mnt.