CELE: Installing and configuring Linux study guide

This domain, Installing and configuring Linux, covers taking a machine from bare metal or a virtual disk to a bootable, configured host: disk layout, filesystems, persistent mounts, bootloader configuration, and post-install settings such as hostname, timezone, and the first administrative user.

Planning and layout

Partition tables: MBR (four primary partitions, extended/logical workaround) versus GPT (many partitions, required for UEFI boot with an EFI System Partition).
Typical layout: ESP at /boot/efi, /boot, /, swap (partition or file), optionally separate /var and /home. LVM adds volume groups and logical volumes that can be resized.
Filesystems: ext4 (journaling, can shrink offline), XFS (large files, cannot shrink), vfat for the ESP. Create with mkfs.ext4 or mkfs.xfs, activate swap with mkswap and swapon.
Persistence lives in /etc/fstab: device (prefer UUID=), mount point, type, options, dump, fsck order. blkid prints UUIDs.
GRUB2 configuration is generated: edit /etc/default/grub, then grub2-mkconfig -o /boot/grub2/grub.cfg on RHEL or update-grub on Debian. Kernel changes may need dracut -f or update-initramfs -u.

Worked example

Add a new 10 GB disk as /data. Partition with fdisk /dev/sdb, run mkfs.xfs /dev/sdb1, mkdir /data, read the UUID with blkid /dev/sdb1, then add UUID=... /data xfs defaults,nofail 0 2 to fstab and run systemctl daemon-reload followed by mount -a. Reasoning: the UUID survives device renaming, nofail stops a missing disk from blocking boot, and mount -a validates the entry before you reboot.

Traps

Putting /dev/sdX names in fstab, where they can reorder.
Installing the bootloader to the wrong disk on a multi-disk system.
Forgetting the ESP mount point in a UEFI install.
Changing GRUB defaults without regenerating grub.cfg.