Configure Linux Red Hat 7 LVM via Ansible

Table of Contents

• Short Description
• Full Description
• Creat Volume for VM via AWS
  • Create Volume
  • Attach Volume
  • Modify Volume
• Add File System on Volume
• Increase File System with New Volume
• Increase File System with Volume Resize
• Decrease File System

Short Description

Ansible LVM

Full Description

LVM configuration using Ansible 2.4/2.5 in Red Hat Enterprise Linux (RHEL) 7.4/7.5.

Creat Volume for VM via AWS

You can create an Amazon EBS volume that you can then attach to any EC2 instance within the same Availability Zone.

Create Volume

1st, open Amazon EC2 console.

2nd, from the navigation bar, select the region in which you would like to create your volume. In the navigation pane, choose ELASTIC BLOCK STORE, Volumes. See images below:

3rd, choose Create Volume. See images below:

4th, for Volume Type, choose a volume type. For Size (GiB), type the size of the volume. For Availability Zone, choose the Availability Zone in which to create the volume. EBS volumes can only be attached to EC2 instances within the same Availability Zone. Choose Create Volume. See images below:

5th, choose Close. See images below:

Attach Volume

1st, open Amazon EC2 console.

2nd, in the navigation pane, choose Elastic Block Store, Volumes. Select an available volume and choose Actions, Attach Volume. See images below:

3rd, for Instance, start typing the name or ID of the instance. Select the instance from the list of options (only instances that are in the same Availability Zone as the volume are displayed). See images below:

4th, for Device, you can keep the suggested device name. Choose Attach. See images below:

Modify Volume

1st, open Amazon EC2 console.

2nd, in the navigation pane, choose Elastic Block Store, Volumes. Select an available volume and choose Actions, Modify Volume. See images below:

3rd, for Size, type the new size of the volume. Choose Modify. See image below:

4th, choose Yes. See image below:

5th, choose Close. See image below:

Add File System on Volume

Install lvm2:

$ sudo yum install -y lvm2

List block devices:

$ lsblk -d

Where:

• -d or --nodeps -- do not print holder devices or slaves.

Example:

$ lsblk -d
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0    0  15G  0 disk
xvdf 202:80   0   1G  0 disk

Ceate a new physical volume with the pvcreate command:

$ sudo pvcreate PV

Where:

• PV -- name of physical volume.

Example:

$ sudo pvcreate /dev/xvdf
Physical volume "/dev/xvdf" successfully created.

Check physical volumes

$ sudo pvscan
PV /dev/xvdf                      lvm2 [1,00 GiB]
Total: 1 [1,00 GiB] / in use: 0 [0   ] / in no VG: 1 [1,00 GiB]

or

$ sudo pvs
PV         VG Fmt  Attr PSize PFree
/dev/xvdf     lvm2 ---  1,00g 1,00g

or

$ pvdisplay
"/dev/xvdf" is a new physical volume of "1,00 GiB"
--- NEW Physical volume ---
PV Name               /dev/xvdf
VG Name
PV Size               1,00 GiB
Allocatable           NO
PE Size               0
Total PE              0
Free PE               0
Allocated PE          0
PV UUID               yWyrLo-K2DT-3GBP-D5YE-NeRL-3ef1-NJyX59

Ceate a new volume group with the vgcreate command:

$ sudo vgcreate VG PV

Where:

• VG -- name of volume group,
• PV -- name ofphysical volume.

Example:

$ sudo vgcreate 0001vg /dev/xvdf
Volume group "0001vg" successfully created

Check volume group

$ sudo vgscan
Reading volume groups from cache.
Found volume group "0001vg" using metadata type lvm2

or

$ sudo vgs
VG     #PV #LV #SN Attr   VSize    VFree
0001vg   1   0   0 wz--n- 1020,00m 1020,00m

or

$ sudo vgdisplay
--- Volume group ---
VG Name               0001vg
System ID
Format                lvm2
Metadata Areas        1
Metadata Sequence No  1
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                0
Open LV               0
Max PV                0
Cur PV                1
Act PV                1
VG Size               1020,00 MiB
PE Size               4,00 MiB
Total PE              255
Alloc PE / Size       0 / 0
Free  PE / Size       255 / 1020,00 MiB
VG UUID               eeHHEq-UIRp-AnLf-bN2D-vnlo-G2a2-mQRPVE

Ceate a new logical volume with the lvcreate command:

$ sudo lvcreate -l PERCENTAGE -n LV VG

Where:

• -l or --extents -- specify a percentage of the remaining free space in a volume group as the size of the logical volume,
• PERCENTAGE -- percentage,
• -n or --name -- specify the name of logical volume,
• LV -- name of logical volume,
• VG -- name of volume group.

The following command creates the logical volume called 0001lv that uses all of the unallocated space in the volume group 0001vg:

$ sudo lvcreate -l 100%FREE -n 0001lv 0001vg
Logical volume "0001lv" created.

Check logical volumes

$ sudo lvscan
ACTIVE            '/dev/0001vg/0001lv' [1020,00 MiB] inherit

or

$ sudo lvs
LV     VG     Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
0001lv 0001vg -wi-a----- 1020,00m

or

$ sudo lvdisplay
--- Logical volume ---
LV Path                /dev/0001vg/0001lv
LV Name                0001lv
VG Name                0001vg
LV UUID                Png2PJ-zsDh-HR3W-UPBm-jHo0-VAWP-iI32lf
LV Write Access        read/write
LV Creation host, time ip-172-31-21-64.eu-west-1.compute.internal, 2018-05-01 13:26:54 +0000
LV Status              available
# open                 0
LV Size                1020,00 MiB
Current LE             255
Segments               1
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:0

Build/format a Linux file system

$ sudo mkfs.FSTYPE LV

Where:

• FSTYPE -- type of file system,
• LV -- name of logical volume.

Example:

$ sudo mkfs.xfs /dev/0001vg/0001lv
meta-data=/dev/0001vg/0001lv     isize=512    agcount=4, agsize=65280 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=261120, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=855, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Check type of file system

$ sudo parted -l
Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/0001vg-0001lv: 1070MB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:

Number  Start  End     Size    File system  Flags
 1      0,00B  1070MB  1070MB  xfs

Mount logical volume temporary

$ sudo mkdir /test
$ sudo mount /dev/0001vg/0001lv /test

Mount logical volume permanently

1st, unmoumt volume and open /etc/fstab file:

$ sudo umount /test
$ sudo yum install -y nano
$ sudo nano /etc/fstab
#
# /etc/fstab
# Created by anaconda on Fri Mar 23 17:41:14 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=50a9826b-3a50-44d0-ad12-28f2056e9927 /                       xfs     defaults        0 0

2nd, manually add next line in /etc/fstab file:

/dev/0001vg/0001lv		/test		xfs		defaults		0 0

Example:

#
# /etc/fstab
# Created by anaconda on Fri Mar 23 17:41:14 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=50a9826b-3a50-44d0-ad12-28f2056e9927 /                       xfs     defaults        0 0
/dev/0001vg/0001lv		/test		xfs		defaults		0 0

3rd, check result:

$ sudo mount -a
$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
/dev/mapper/0001vg-0001lv 1017M   33M  985M   4% /test

Increase File System with New Volume

1st, create new volume and attach volume to VM.

2nd, list block devices:

$ lsblk -d

Where:

• -d or --nodeps -- do not print holder devices or slaves.

Example:

$ lsblk -d
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0    0  15G  0 disk
xvdf 202:80   0   1G  0 disk
xvdg 202:96   0   1G  0 disk

3rd, ceate a new physical volume with the pvcreate command:

$ sudo pvcreate PV

Where:

• PV -- name of physical volume.

Example:

$ sudo pvcreate /dev/xvdg
Physical volume "/dev/xvdg" successfully created.

4th, use the vgextend command to extend the volume group:

$ sudo vgextend VG PV

Where:

• VG -- name of volume group,
• PV -- name of physical volume.

Example:

$ sudo vgextend 0001vg /dev/xvdg
Volume group "0001vg" successfully extended

5th, once the volume group is large enough to include the larger file system, extend the logical volume with lvextend or lvresize command.

$ sudo lvextend -r -l PERCENTAGE LV

Where:

• -r or --resizefs -- resize file system,
• -l or --extents -- specify a percentage of the remaining free space in a volume group,
• PERCENTAGE -- percentage,
• LV -- name of logical volume.

The following command extend the logical volume called 0001lv to fill all of the unallocated space in the volume group 0001vg:

$ sudo lvextend -r -l +100%FREE /dev/0001vg/0001lv
Size of logical volume 0001vg/0001lv changed from 1020,00 MiB (255 extents) to 1,99 GiB (510 extents).
Logical volume 0001vg/0001lv successfully resized.
meta-data=/dev/mapper/0001vg-0001lv isize=512    agcount=4, agsize=65280 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=261120, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=855, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 261120 to 522240

Increase File System with Volume Resize

1st, list block devices:

$ lsblk -d

Where:

• -d or --nodeps -- do not print holder devices or slaves.

Example:

$ lsblk -d
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0    0  15G  0 disk
xvdf 202:80   0   1G  0 disk

2nd, modify volume and list block devices again:

$ lsblk -d
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0    0  15G  0 disk
xvdf 202:80   0   2G  0 disk

3rd, reread partition table and resize physical volume with the pvresize command:

$ sudo blockdev --rereadpt /dev/xvdf
$ sudo pvresize /dev/xvdf
Physical volume "/dev/xvdf" changed
1 physical volume(s) resized / 0 physical volume(s) not resized

4th, extend the logical volume with lvextend or lvresize command.

$ sudo lvextend -r -l PERCENTAGE LV

Where:

• -r or --resizefs -- resize file system,
• -l or --extents -- specify a percentage of the remaining free space in a volume group,
• PERCENTAGE -- percentage,
• LV -- name of logical volume.

The following command extend the logical volume called 0001lv to fill all of the unallocated space in the volume group 0001vg:

$ sudo lvextend -r -l +100%FREE /dev/0001vg/0001lv
Size of logical volume 0001vg/0001lv changed from 1020,00 MiB (255 extents) to <2,00 GiB (511 extents).
Logical volume 0001vg/0001lv successfully resized.
meta-data=/dev/mapper/0001vg-0001lv isize=512    agcount=4, agsize=65280 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=261120, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=855, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 261120 to 523264

Decrease File System

Remember, please, solution does not work with XFS file system:

$ sudo lvreduce -r -L -100 /dev/0001vg/0001lv
fsadm: Xfs filesystem shrinking is unsupported.
/usr/sbin/fsadm failed: 1
Filesystem resize failed.

Reduce the size of logical volume with lvreduce command

$ sudo lvreduce -r -L SIZE LV

Where:

• -r or --resizefs -- resize underlying filesystem together with the logical volume,
• -L or --size -- reduce or set the logical volume size in units of megabytes,
• SIZE -- size in units of megabytes. A size suffix of g for gigabytes, t for terabytes, p for petabytes is optional. With the - sign the value will be subtracted from the logical volume's actual size and without it it will be taken as an absolute size,
• LV -- name of logical volume.

Example:

$ sudo lvreduce -r -L -100 /dev/0001vg/0001lv
Do you want to unmount "/test" ? [Y|n] y
fsck from util-linux 2.23.2
/dev/mapper/0001vg-0001lv: 11/130816 files (0.0% non-contiguous), 17948/523264 blocks
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/mapper/0001vg-0001lv to 497664 (4k) blocks.
The filesystem on /dev/mapper/0001vg-0001lv is now 497664 blocks long.

Size of logical volume 0001vg/0001lv changed from <2,00 GiB (511 extents) to <1,90 GiB (486 extents).
Logical volume 0001vg/0001lv successfully resized.

Remember, only Btrfs and ZFS can be shrunk online.