LVM.md

Checking free space:

lsblk # list disk and filesystems
vgs # check free space
parted /dev/sde unit GB print free | grep GB           # check free space on raw drive
parted /dev/sda unit GB print free | grep 'Free Space' | tail - n1 | awk '{print $3}'

Formatting new drive (NEED TO REWRITE THIS ONE - IGNORE)

fdisk /dev/sdb
n
p
1
t
8e
w

Creating new pv volume

pvcreate /dev/sdb1
# pvs
  PV              VG               Fmt   Attr      PSize      PFree
  /dev/sda2  VolGroup00 lvm2 a--u    49.72g     32.84g
  /dev/sdb1  VolGroup00 lvm2 a--u    249.97g    0

Creating new volume group

vgcreate docker-vg /dev/sde1 /dev/sdf1 /dev/sdg1

Extending existing volume group

vgextend docker-vg /dev/sdb1

Creating new Logical Volume

lvcreate -n docker-vg-sn -L 250G VolGroup00 # standard way
lvcreate -n docker-vg-myapp VolGroup01 -l +100%free /dev/sde1 # this can be useful also

Listing Logical Volume

root@docker:~# lvs
  LV        VG        Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  docker    docker-vg -wi-ao----  30.00g
  ubuntu-lv ubuntu-vg -wi-ao---- <24.00g
root@docker:~# lvs -o +devices # this can be useful also

Adding new file system

Or manually:

mkfs.ext4 /dev/mapper/docker--vg-volumes
mkdir /opt/docker/volumes/
echo '/dev/mapper/docker--vg-docker--vg--volumes  /opt/docker/volumes/   ext4        defaults,nodev   1       2' >> /etc/fstab
mount /opt/docker/volumes/
df -h

Or with Ansible:

cd /apps/ansible
ansible-playbook /apps/ansible/playbooks/rhel/localuser/localuser.yml -i /home/sca37/ansible_host_files/localuser_hosts -e target=PEOPLEDAT -e groupname=psoft -e username=psoftadm

LVS extend:

extend underlayer root lvm volume in 1Gb

lvextend -L +750M /dev/mapper/VolGroup00-apps_apache -r                                                  # -r option will refresh it after that that will add 750M more to existing volume (so for example 1G +750M = 1.75G)
lvextend -L 2G /dev/mapper/VolGroup00-apps_apache -r                                                     # that will setup new volume size to exactly 2 GB
lvextend -l +100%free /dev/mapper/VolGroup00-cmmapdbprd--ora--archivelog01 /dev/sdc1                     # this can be useful too

online resize the apache filesystem

resize2fs /dev/mapper/VolGroup00-apps_apache

confirm the new size is 1G

df -h /apps/apache/

LVS manual remove:

umount /apss/cooker
vi /etc/fstab # then remove automount
lvremove apps_cooker

Back out

Detail the steps to backout the change.

Contact with application owner and ask for stop it.

umount /apps/ora
lvdisplay dev/mapper/VolGroup00-apps_ora
lvreduce -L 6G /dev/mapper/VolGroup00-apps_ora
resize2fs /dev/mapper/VolGroup00-apps_ora
mount /apps/ora
df -h /apps/ora

How long will it take (ensuring the timings for the change include the backout)?

Around 5 min At what point will a decision be made to backout if required? If file system cannot be resized. DO NOT REDUCE correctly resized file system without umount!

Have you tested your backout and what was the outcome, if not why are you unable to test the backout?

This is standard unix task and don't  need testing. 

Risk Assessment

What services will be impacted during the implementation and how will they be impacted? It's full online change - no service impact. If the change went wrong what services are at risk and how could they be affected? Very unlikely worst case scenario: Integration Hub lost file system. What is the chance of these services being affected and why? Very unlikely

Another useful comand:

Rescan device:

/bin/echo 1 > /sys/block/sda/device/rescan

List all devices:

root@ud003671 # lsblk
NAME                                         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
fd0                                            2:0    1    4K  0 disk
sda                                            8:0    0   60G  0 disk
├─sda1                                         8:1    0  256M  0 part /boot
└─sda2                                         8:2    0 59.8G  0 part
  ├─VolGroup00-rootLV                        253:0    0    8G  0 lvm  /
  ├─VolGroup00-swapLV                        253:1    0   16G  0 lvm  [SWAP]
  ├─VolGroup00-tmpLV                         253:2    0    1G  0 lvm  /tmp
  ├─VolGroup00-varLV-real                    253:3    0    4G  0 lvm
  │ ├─VolGroup00-varLV                       253:4    0    4G  0 lvm  /var
  │ └─VolGroup00-varLV_snap                  253:6    0    4G  0 lvm
  ├─VolGroup00-var_log_audit                 253:7    0  608M  0 lvm  /var/log/audit
  ├─VolGroup00-appsLV                        253:8    0    1G  0 lvm  /apps
  ├─VolGroup00-var_crash                     253:9    0    1G  0 lvm  /var/crash
  ├─VolGroup00-apps_nagios                   253:10   0  256M  0 lvm  /apps/nagios
  ├─VolGroup00-apps_ora                      253:11   0   20G  0 lvm  /apps/ora
  ├─VolGroup00-favapdbt01                    253:12   0  100M  0 lvm  /favapdbt01
  └─VolGroup00-favapdbt01--ora--fra          253:15   0   25G  0 lvm  /favapdbt01/ora/fra
sdb                                            8:16   0  140G  0 disk
├─VolGroup00-favapdbt01--ora                 253:13   0  160G  0 lvm  /favapdbt01/ora
├─VolGroup00-favapdbt01--ora--archivelog01   253:14   0   55G  0 lvm  /favapdbt01/ora/archivelog01
└─VolGroup00-favapdbt01--ora--fra            253:15   0   25G  0 lvm  /favapdbt01/ora/fra
sdc                                            8:32   0  100G  0 disk
└─sdc1                                         8:33   0  100G  0 part
  ├─VolGroup00-varLV_snap-cow                253:5    0  512M  0 lvm
  │ └─VolGroup00-varLV_snap                  253:6    0    4G  0 lvm
  ├─VolGroup00-favapdbt01--ora               253:13   0  160G  0 lvm  /favapdbt01/ora
  ├─VolGroup00-favapdbt01--ora--archivelog01 253:14   0   55G  0 lvm  /favapdbt01/ora/archivelog01
  ├─VolGroup00-favapdbt01--ora--fra          253:15   0   25G  0 lvm  /favapdbt01/ora/fra
  └─VolGroup00-OSbackup                      253:16   0  5.4G  0 lvm
sdd                                            8:48   0  100G  0 disk
sde                                            8:64   0  100G  0 disk
sr0