RHCSA Practical Lab Series – Creating a Logical Volume

🔍 Lab 20: Configuring Logical Volumes in RHEL 9

📌 Objective

In this lab, you will:

✔ Create a new logical volume using an available disk (/dev/vdb)
✔ Allocate 60 extents (PE) for the logical volume
✔ Format the volume using vfat filesystem
✔ Automount the logical volume at /mnt/qa

📌 Step 1: Identify Available Disks and Partitions

🔹 Check the available disks and partitions:

[root@node2 ~]# lsblk

📌 Expected Output (Example):

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vda    252:0    0   20G  0 disk
├─vda1 252:1    0    1G  0 part /boot
└─vda2 252:2    0   19G  0 part /
vdb    252:16   0    5G  0 disk

✅ Ensure vdb is available before proceeding.

📌 Step 2: Create a New Partition

🔹 Use fdisk to create a new partition:

[root@node2 ~]# fdisk /dev/vdb

📌 Inside the fdisk prompt, follow these steps:

1. Press n → Create a new partition
2. Press p → Make it a primary partition
3. Press 2 → Assign partition number 2
4. Press Enter twice → Accept default start and end sectors
5. Specify a partition size of at least 200M (e.g., +1200M)
6. Press w → Write changes and exit

✅ Verify the new partition:

[root@node2 ~]# lsblk

📌 Expected Output:

vdb    252:16   0    5G  0 disk
├─vdb1 252:17   0  2.5G  0 part
└─vdb2 252:18   0  1.2G  0 part

📌 Step 3: Create a Volume Group & Logical Volume

🔹 Initialize the partition for LVM usage:

[root@node2 ~]# vgcreate -s 16M qagroup /dev/vdb2

📌 Explanation:

• vgcreate → Creates a Volume Group named qagroup
• -s 16M → Sets the physical extent size to 16M
• /dev/vdb2 → Uses the newly created partition

🔹 Create the Logical Volume (qa) with 60 extents:

[root@node2 ~]# lvcreate -l 60 -n qa qagroup

📌 Explanation:

• -l 60 → Allocates 60 extents to the LV
• -n qa → Names the LV as qa
• qagroup → Associates it with the Volume Group

✅ Check Logical Volume Details:

[root@node2 ~]# lvdisplay /dev/qagroup/qa

📌 Expected Output:

LV Name                /dev/qagroup/qa
VG Name                qagroup
LV Size                960.00 MiB

📌 Step 4: Format the Logical Volume

🔹 Install mkfs.vfat (if missing):

[root@node2 ~]# yum provides */mkfs.vfat
[root@node2 ~]# yum -y install dosfstools

🔹 Format the LV with vfat filesystem:

[root@node2 ~]# mkfs.vfat /dev/qagroup/qa

✅ Expected Output:

mkfs.vfat 3.0.26 (2014-03-07)

📌 Step 5: Mount the Logical Volume

🔹 Create a mount point:

[root@node2 ~]# mkdir /mnt/qa

🔹 Mount the LV manually:

[root@node2 ~]# mount /dev/qagroup/qa /mnt/qa

🔹 Verify the mount:

[root@node2 ~]# df -h

✅ Expected Output:

Filesystem                Size  Used Avail Use% Mounted on
/dev/qagroup/qa          960M  1M   959M   1% /mnt/qa

📌 Step 6: Automount Logical Volume at Boot

🔹 Edit /etc/fstab:

[root@node2 ~]# vim /etc/fstab

🔹 Append the following line:

/dev/qagroup/qa  /mnt/qa  vfat  defaults  0  0

✅ Save and exit (ESC + :wq).

🔹 Test automount:

[root@node2 ~]# mount -a
[root@node2 ~]# df -h

✅ If /mnt/qa appears, the automount configuration is correct.

📌 Step 7: Verify After Reboot (Optional)

🔹 Reboot the system:

[root@node2 ~]# reboot

🔹 After reboot, check if the LV is still mounted:

[root@node2 ~]# df -h

✅ If /mnt/qa is still mounted, everything is correctly configured!

📌 Troubleshooting Tips

🔹 If vgcreate fails, check if LVM tools are installed:

[root@node2 ~]# yum install -y lvm2

🔹 If mkfs.vfat fails, ensure the package is installed:

[root@node2 ~]# yum provides */mkfs.vfat

🔹 If /mnt/qa does not mount after reboot, check /etc/fstab syntax:

[root@node2 ~]# cat /etc/fstab

✅ Ensure there are no typos or missing fields!

✅ Final Summary

✔ Created a new logical volume (qa) using LVM
✔ Formatted it with vfat filesystem
✔ Mounted it at /mnt/qa
✔ Configured automount via /etc/fstab
✔ Verified everything after reboot

📌 Next Lab: Configuring System Performance Optimization with tuned

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