Tech Tutorial: Configure Local Storage on RHEL #

Introduction #

In this tutorial, we will explore how to manage local storage on a Red Hat Enterprise Linux (RHEL) system. Specifically, we will learn how to add new partitions and logical volumes, and configure swap space non-destructively. This skill is crucial for system administrators looking to manage storage effectively while ensuring system stability and scalability.

Prerequisites #

A RHEL installed system (version 7 or 8)
Root or sudo access
Basic understanding of Linux command line interface

Step-by-Step Guide #

Step 1: Preparing the Disk #

Before adding new partitions or logical volumes, you need to identify the available disks. Use the lsblk command to list all block devices:

sudo lsblk

Look for a disk with free space or no partitions. For this tutorial, we assume /dev/sdb is the target disk.

Step 2: Creating a New Partition #

We will use fdisk to create a new primary partition on /dev/sdb.

Start fdisk on /dev/sdb:
```
sudo fdisk /dev/sdb
```
Press n to create a new partition.
Choose p for primary partition.
Enter the partition number (e.g., 1).
Specify the first and last sectors or simply press Enter to use the default, which utilizes the entire disk.
Press w to write the changes to the disk.

Verify the new partition with lsblk:

sudo lsblk

Step 3: Creating a Physical Volume #

After creating the partition, convert it into a physical volume (PV) for use in a logical volume:

sudo pvcreate /dev/sdb1

Verify the physical volume:

sudo pvs

Step 4: Creating a Volume Group #

Create a new volume group (VG) by adding the physical volume to it:

sudo vgcreate vgdata /dev/sdb1

Check the created volume group:

sudo vgs

Step 5: Adding a Logical Volume #

Now, create a logical volume (LV) within the vgdata volume group:

sudo lvcreate -n lvdata -L 10G vgdata

This command creates a logical volume named lvdata with a size of 10GB.

Verify the logical volume:

sudo lvs

Step 6: Formatting and Mounting the Logical Volume #

Format the logical volume with the ext4 filesystem:

sudo mkfs.ext4 /dev/vgdata/lvdata

Create a mount point and mount the logical volume:

sudo mkdir /mnt/data
sudo mount /dev/vgdata/lvdata /mnt/data

Ensure the mount is permanent by adding it to /etc/fstab:

/dev/vgdata/lvdata /mnt/data ext4 defaults 0 0

Step 7: Configuring Swap Space #

To add swap:

Create a swap logical volume:
```
sudo lvcreate -n lvswap -L 2G vgdata
```
Make the logical volume a swap area:
```
sudo mkswap /dev/vgdata/lvswap
```
Activate the swap:
```
sudo swapon /dev/vgdata/lvswap
```

Add it to /etc/fstab for permanence:

/dev/vgdata/lvswap swap swap defaults 0 0

Verify the swap is active:

sudo swapon -s

Conclusion #

In this tutorial, we’ve covered how to efficiently manage local storage on a RHEL system by creating partitions, physical volumes, volume groups, logical volumes, and configuring swap space, all without disrupting the system. These steps are essential for system administrators preparing for the RHCSA or managing RHEL systems in production environments. Remember, practice and familiarity with system tools are key to effective and efficient system administration.