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lvm basics

physical volumes

# pvs
  PV         VG     Fmt  Attr PSize   PFree  
  /dev/sda2  vg_790 lvm2 a--  465.52g 211.52g

list physical volumes

# pvdisplay 

# pvdisplay  -C

volume groups

# vgs
  VG     #PV #LV #SN Attr   VSize   VFree  
  vg_790   1  10   0 wz--n- 465.52g 211.52g

list all volume groups

# vgscan

# vgdisplay

# vgdisplay -C

activate all 

# vgchange -ay

deactivate a specific volume group

# vgchange -an vol_group_1

activate all logical volumes on a volume group, only

# vgchange -ay vol_group_1

logical volumes

list logical volumes

# lvs

# lvdisplay -C

Create a new LVM partition

# lvcreate -L 10G -n /dev/vg_group01/lv_vol01 

# mkfs.ext4 -L lv_vol01 /dev/vg_group01/lv_vol01 

# mount /dev/vg_group01/lv_vol01 /media/

extend an lvm partition

How to extend an lvm partition:

umount /opt/dnl

lvextend -L +5G /dev/vg01/dnl

e2fsck -f /dev/vg01/dnl

resize2fs /dev/vg01/dnl 

mount /opt/dnl/

reduce

# df -h /opt/

Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/vg_xps-lv_optfs   69G   44G   23G  66% /opt

The goal is to reduce from 70G to 50G

umount

# umount /opt/

check filesystem

check a Linux ext2/ext3/ext4 file system

# e2fsck -ff /dev/mapper/vg_xps-lv_optfs 


e2fsck 1.43.9 (8-Feb-2018)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
optfs: 117811/4587520 files (0.4% non-contiguous), 11609065/18350080 blocks

resize2fs filesystem

resize2fs – ext2/ext3/ext4 file system resizer

# resize2fs /dev/mapper/vg_xps-lv_optfs 50G 

resize2fs 1.43.9 (8-Feb-2018)
Resizing the filesystem on /dev/mapper/vg_xps-lv_optfs to 13107200 (4k) blocks.
The filesystem on /dev/mapper/vg_xps-lv_optfs is now 13107200 (4k) blocks long.

LVM reduce

# lvreduce -L -20G /dev/mapper/vg_xps-lv_optfs 
  WARNING: Reducing active logical volume to 50.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)

Do you really want to reduce vg_xps/lv_optfs? [y/n]: y

  Size of logical volume vg_xps/lv_optfs changed from 70.00 GiB (17920 extents) to 50.00 GiB (12800 extents).
  Logical volume vg_xps/lv_optfs successfully resized.

verify

# mount /opt/

# df -h /opt/

Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/vg_xps-lv_optfs   50G   44G  3.6G  93% /opt

resize to 100%

# lvresize -l +100%FREE -n /dev/vg01/backup

resize xfs 

LVM resize

# lvresize -l +100%FREE -n /dev/vg_xps/lv_Breach

  Size of logical volume vg_xps/lv_Breach changed from 5.00 GiB (1280 extents) to <6.97 GiB (1784 extents).
  Logical volume vg_xps/lv_Breach successfully resized.

xfs grow

# xfs_growfs /opt/Breach