Exercise 2: Disk Management - Managing Logical Volume
Here are some key issues pertaining to managing logical volumes that have been addressed and are crucial for exam preparation.
Managing Logical Volume
Q1. Create a volume group named pisvg of 1GB into the disk /dev/sdc. Make sure that the extent size is of 8MB while creating the volume group.
# First check the details of the the disk, we can see that no file system is present.
[root@server ~]# blkid /dev/nvme0n3
[root@server ~]# lsblk | grep nvme0n3
nvme0n3 259:7 0 6G 0 disk
[root@server ~]# pvcreate /dev/nvme0n3p1
[root@server ~]# blkid /dev/nvme0n3p1
/dev/nvme0n3: UUID="mRBaPO-mXau-vjS3-cbwe-Uk39-ArGJ-xwoir5" TYPE="LVM2_member"
[root@server ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/nvme0n1p3 cs lvm2 a-- 18.41g 0
/dev/nvme0n3p1 pisvg lvm2 a-- 1016.00m 1016.00m
[root@server ~]# vgcreate -s 8M pisvg /dev/nvme0n3p1
[root@server ~]# vgdisplay
--- Volume group ---
VG Name pisvg
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 1016.00 MiB
PE Size 8.00 MiB
Total PE 127
Alloc PE / Size 0 / 0
Free PE / Size 127 / 1016.00 MiB
VG UUID XxSDbc-ErV1-U1YL-MMds-a04i-jXOA-LiaO38
Q2. Create a logical volume named pislv1 of 200MB, format it with XFS filesystem and mount it permanently on /pisdata2 directory.
# Creating LV from VG with size 200M and name pislv1
[root@server ~]# lvcreate -n pislv1 -L 200M pisvg
Logical volume "pislv1" created.
[root@server ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root cs -wi-ao---- 16.41g
swap cs -wi-ao---- 2.00g
pislv1 pisvg -wi-a----- 200.00m
[root@server ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sr0 11:0 1 1024M 0 rom
nvme0n1 259:0 0 20G 0 disk
├─nvme0n1p1 259:1 0 600M 0 part /boot/efi
├─nvme0n1p2 259:2 0 1G 0 part /boot
└─nvme0n1p3 259:3 0 18.4G 0 part
├─cs-root 253:0 0 16.4G 0 lvm /
└─cs-swap 253:1 0 2G 0 lvm [SWAP]
nvme0n2 259:4 0 5G 0 disk
├─nvme0n2p1 259:5 0 1G 0 part /pisdata1
└─nvme0n2p2 259:6 0 512M 0 part [SWAP]
nvme0n3 259:7 0 6G 0 disk
└─nvme0n3p1 259:9 0 1G 0 part
└─pisvg-pislv1 253:2 0 200M 0 lvm
[root@server ~]# blkid /dev/pisvg/pislv1
# Making XFS File system
[root@server ~]# mkfs.xfs /dev/pisvg/pislv1
Filesystem should be larger than 300MB.
Log size should be at least 64MB.
Support for filesystems like this one is deprecated and they will not be supported in future releases.
meta-data=/dev/pisvg/pislv1 isize=512 agcount=4, agsize=12800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1 bigtime=1 inobtcount=1 nrext64=0
data = bsize=4096 blocks=51200, 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
# Cheking the file system
[root@server ~]# blkid /dev/pisvg/pislv1
/dev/pisvg/pislv1: UUID="211824be-d4db-47b4-9ee1-c69f7d60677d" TYPE="xfs"
# Mounting Permanently
# Add the following line in the /etc/fstab
[root@server ~]# vim /etc/fstab
/dev/pisvg/pislv1 /pisdata3 xfs defaults 0 0
[root@server ~]# mount -a
mount: (hint) your fstab has been modified, but systemd still uses
the old version; use 'systemctl daemon-reload' to reload.
[root@server ~]# systemctl daemon-reload
[root@server ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sr0 11:0 1 1024M 0 rom
nvme0n1 259:0 0 20G 0 disk
├─nvme0n1p1 259:1 0 600M 0 part /boot/efi
├─nvme0n1p2 259:2 0 1G 0 part /boot
└─nvme0n1p3 259:3 0 18.4G 0 part
├─cs-root 253:0 0 16.4G 0 lvm /
└─cs-swap 253:1 0 2G 0 lvm [SWAP]
nvme0n2 259:4 0 5G 0 disk
├─nvme0n2p1 259:5 0 1G 0 part /pisdata1
└─nvme0n2p2 259:6 0 512M 0 part [SWAP]
nvme0n3 259:7 0 6G 0 disk
└─nvme0n3p1 259:9 0 1G 0 part
└─pisvg-pislv1 253:2 0 200M 0 lvm /pisdata3
Q3. Create another logical volume named pislv2 of 40 extents, format it with EXT3 filesystem and mount it on /pisdata3 directory permanently.
# Creating a logical volume (LV) named pislv2 of 40 extents
[root@server ~]# lvcreate -n pislv2 -L 40M pisvg
Logical volume "pislv2" created.
[root@server ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root cs -wi-ao---- 16.41g
swap cs -wi-ao---- 2.00g
pislv1 pisvg -wi-ao---- 200.00m
pislv2 pisvg -wi-a----- 40.00m
# Format the logical volume (LV) with EXT3 filesystem
[root@server ~]# mkfs.ext3 /dev/pisvg/pislv2
mke2fs 1.46.5 (30-Dec-2021)
Creating filesystem with 40960 1k blocks and 10240 inodes
Filesystem UUID: 5bf2dac6-966e-4595-9c65-894b4e7956e7
Superblock backups stored on blocks:
8193, 24577
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
[root@server ~]# blkid /dev/pisvg/pislv2
/dev/pisvg/pislv2: UUID="5bf2dac6-966e-4595-9c65-894b4e7956e7" SEC_TYPE="ext2" TYPE="ext3"
# Mount the logical volume (LV) on /pisdata3 directory permanently
# Add the following line below
[root@server ~]# vim /etc/fstab
/dev/pisvg/pislv2 /pisdata3 ext4 defaults 0 0
[root@server ~]# mount -a
mount: (hint) your fstab has been modified, but systemd still uses
the old version; use 'systemctl daemon-reload' to reload.
[root@server ~]# systemctl daemon-reload
[root@server ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sr0 11:0 1 1024M 0 rom
nvme0n1 259:0 0 20G 0 disk
├─nvme0n1p1 259:1 0 600M 0 part /boot/efi
├─nvme0n1p2 259:2 0 1G 0 part /boot
└─nvme0n1p3 259:3 0 18.4G 0 part
├─cs-root 253:0 0 16.4G 0 lvm /
└─cs-swap 253:1 0 2G 0 lvm [SWAP]
nvme0n2 259:4 0 5G 0 disk
├─nvme0n2p1 259:5 0 1G 0 part /pisdata1
└─nvme0n2p2 259:6 0 512M 0 part [SWAP]
nvme0n3 259:7 0 6G 0 disk
└─nvme0n3p1 259:9 0 1G 0 part
├─pisvg-pislv1 253:2 0 200M 0 lvm /pisdata3
└─pisvg-pislv2 253:3 0 40M 0 lvm /pisdata3
Q4. Resize of the logical volume pislv1 to 400MB.
[root@server ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root cs -wi-ao---- 16.41g
swap cs -wi-ao---- 2.00g
pislv1 pisvg -wi-ao---- 200.00m
pislv2 pisvg -wi-ao---- 400.00m
[root@server ~]# lvextend -L +200M /dev/pisvg/pislv1
Size of logical volume pisvg/pislv1 changed from 200.00 MiB (25 extents) to 400.00 MiB (50 extents).
Logical volume pisvg/pislv1 successfully resized.
[root@server ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root cs -wi-ao---- 16.41g
swap cs -wi-ao---- 2.00g
pislv1 pisvg -wi-ao---- 400.00m
pislv2 pisvg -wi-ao---- 400.00m Q5. Resize the logical volume pislv2 to 1200MB. If there is no sufficient free space in the VG to extend the logical volume, then use the disk /dev/sdd to extend size of the VG.
# Creating a Physical Volume
[root@server ~]# pvcreate /dev/nvme0n4
Physical volume "/dev/nvme0n4" successfully created.
[root@server ~]# blkid /dev/nvme0n4
/dev/nvme0n4: UUID="roiwO7-OG8m-Ft7e-5Edn-Ygg5-Ehep-Qmsx5q" TYPE="LVM2_member"
# Viewing the created PV
[root@server ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/nvme0n1p3 cs lvm2 a-- 18.41g 0
/dev/nvme0n3p1 pisvg lvm2 a-- 1016.00m 216.00m
/dev/nvme0n4 lvm2 --- 5.00g 5.00g
# Extending the VG to the Created PV
# Viewing the previous VG
[root@server ~]# vgs
VG #PV #LV #SN Attr VSize VFree
cs 1 2 0 wz--n- 18.41g 0
pisvg 1 2 0 wz--n- 1016.00m 216.00m # Previously 1GiB
# Extending the VG
[root@server ~]# vgextend pisvg /dev/nvme0n4
Volume group "pisvg" successfully extended
# Viewing the extended VG
[root@server ~]# vgs
VG #PV #LV #SN Attr VSize VFree
cs 1 2 0 wz--n- 18.41g 0
pisvg 2 2 0 wz--n- 5.98g 5.20g # Extended to 5.98GiB, by adding 5GiB of nvme0n4
# Now resizing the pisvg2 to the required capacity 1200M
[root@server ~]# lvextend -L +1000M /dev/pisvg/pislv2
Size of logical volume pisvg/pislv2 changed from 200.00 MiB (25 extents) to 1.17 GiB (150 extents).
Logical volume pisvg/pislv2 successfully resized.
[root@server ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root cs -wi-ao---- 16.41g
swap cs -wi-ao---- 2.00g
pislv1 pisvg -wi-ao---- 200.00m
pislv2 pisvg -wi-a----- 1.17g # Resized to 1200M