1. Installer Fails to Detect Storage Devices
- Cause: Missing or incompatible storage drivers (e.g., for RAID controllers, NVMe, or proprietary hardware).
- Fix:
- Load vendor-provided driver disks (DD) during installation using the dd boot option.
- Use the “Troubleshooting → Rescue a Red Hat system” mode to verify hardware detection.
- Ensure firmware on storage controllers is up to date.
2. Anaconda Installer Crashes or Hangs
- Cause: Hardware incompatibility, insufficient RAM, or corrupted installation media.
- Fix:
- Verify checksum of ISO (sha256sum).
- Recreate a bootable USB using tools like dd or Rufus (in DD mode).
- Boot with inst.text for text-mode installation (less resource-intensive).
- Increase RAM or disable graphical effects via kernel boot options (nomodeset).
3. Network Not Configured During Installation
- Cause: The network interface is not activated by default in Anaconda.
- Fix:
- In the Installation Summary → Network & Host Name, manually enable the interface.
- For headless or automated installs, use a Kickstart file with network configuration:
ks
network –bootproto=dhcp –device=enp0s3 –onboot=on
4. UEFI vs BIOS Boot Confusion
- Issue: System boots in UEFI mode but installer expects BIOS (or vice versa), leading to GRUB failure.
- Fix:
- Ensure consistent boot mode: check firmware settings before installing.
- For UEFI systems, partition disk with a GPT table and include an EFI System Partition (ESP) (~600 MB, FAT32, mounted at /boot/efi).
- Reinstall GRUB if needed:
bash
grub2-install –target=x86_64-efi –efi-directory=/boot/efi –bootloader-id=rhel
5. Subscription Manager / Registration Fails During Install
- Cause: No internet access, proxy misconfiguration, or invalid credentials.
- Fix:
- Skip registration during install; register post-installation:
bash
- subscription-manager register –username <user> –auto-attach
If behind a proxy, configure it in Kickstart or via environment variables.
6. Disk Encryption (LUKS) Issues
- Issue: Forgotten passphrase or failed unlock at boot.
- Mitigation:
- Always back up LUKS headers (cryptsetup luksHeaderBackup).
- Add a backup keyfile (stored securely off-system).
- Test unlocking in rescue mode before rebooting.
7. Post-Install Boot Failure (Black Screen or GRUB Rescue)
- Common Causes:
- Incorrect bootloader installation.
- Secure Boot interfering with unsigned drivers.
- Fix:
- Boot from rescue media and chroot into system to reinstall GRUB.
- Disable Secure Boot temporarily if using third-party drivers.
- Use efibootmgr to verify UEFI boot entries.
8. Time/Date or NTP Misconfiguration
- Impact: Certificate validation failures, Kerberos issues.
- Fix:
- Enable NTP during install or post-install:
bash
timedatectl set-ntp true
systemctl enable –now chronyd
9. SELinux Denials Post-Install
- Not a bug, but often mistaken for one.
- Fix:
- Use audit2why or sealert to interpret denials.
- Adjust policies with setsebool or custom modules—do not disable SELinux in production.
10. Package Selection or Repository Errors
- Cause: Missing repos, expired subscriptions, or incorrect base repos.
- Fix:
- After registration, ensure correct repos are enabled:
bash
subscription-manager repos –enable=rhel-9-for-x86_64-baseos-rpms
- For disconnected environments, configure local mirrors or use ISO as repo.