Migrating to SUSE Linux 16: Key Technical Differences from SLE 15

SLE 15 used Service Packs (SP1 through SP7) for annual updates. SUSE Linux 16 replaces this model with minor releases (for example, 16.0, 16.1), scheduled annually in November.

Each SLE 15 service pack carried 18 months of general support with a 6-month overlap to the next SP. SUSE Linux 16 doubles the overlap:

UEFI is the default for fresh installations of SUSE Linux 16.0. Legacy BIOS support is deprecated and will be removed in a future release. It is retained for backward compatibility in:

Note that some features—such as full disk encryption with TPM—are not available with Legacy BIOS.

The minimum supported microarchitecture levels for SUSE Linux 16 have been raised for most platforms.

SLE 15 used YaST for both installation and ongoing system configuration, with AutoYaST for unattended deployments. SUSE Linux 16 replaces this with Agama—a purpose-built installer that is not a general management tool.

Agama is available in three extractable image flavors:

Agama provides a Web-based front-end, a command-line interface, and an HTTP API. It supports unattended installation and offers a high degree of compatibility with AutoYaST's file format and data schema. However, Agama is not a drop-in replacement for AutoYaST: some profile adjustments are expected. A new, more powerful profile schema based on JSON/Jsonnet is also available.

Unlike AutoYaST, Agama supports repeated configuration import. It is useful for iterative deployment workflows.

The installer medium now uses a standard live medium with dracut, systemd and NetworkManager, and provides a backward-compatibility layer with selected linuxrc options.

Agama installation images no longer ship with a separate rescue system. Until a dedicated rescue image is provided in a future release, you can access a recovery shell by:

Yes, SUSE Linux 16 instances can register against an RMT server for updates. However, the RMT service itself must currently run on a SLE 15 instance, as RMT 15 is fully supported as an installation source for SUSE Linux 16. RMT server support running directly on SUSE Linux 16 is expected to be released with SUSE Linux 16.1.

SUSE Linux 16 ships GRUB 2 version 2.12. BLS and systemd-boot are not used in 16.0 but may be added in future releases. On AMD64/Intel 64, full disk encryption is supported using PCR to unlock the disk, provided the system has a TPM v2.1 or later chip.

SUSE Linux 16 continues the ongoing migration of vendor-supplied default configuration from /etc to /usr/etc. This separation allows administrator customization in /etc to survive maintenance updates without being overwritten.

To customize the configuration of a service, you have three options (using a hypothetical tool frobnicator as an example):

Important: Blind updates to /etc

Tools that blindly create or overwrite files in /etc can produce unexpected results. For example, creating an empty /etc/ssh/sshd_config file may lock you out of SSH access. Review the full list of affected packages at https://en.opensuse.org/openSUSE:Packaging_UsrEtc.

In SLE 15, /tmp was a regular directory or Btrfs subvolume. In SUSE Linux 16, /tmp uses tmpfs, which stores data in RAM and/or swap space.

Important: /tmp is not persistent across reboots

Any data written to /tmp is lost on reboot. Adapt applications that write persistent data to /tmp to use a different location such as /var/cache.

Warning: Do not oversize tmpfs

Setting tmpfs beyond the sum of physical RAM and swap can cause deadlock situations. Size /tmp accordingly.

SLE 15 used systemd as the default but retained compatibility for third-party SysV init scripts. SUSE Linux 16 completes the transition: SysV init scripts are removed. All services must use standard systemd units.

Yes. While unsupported in SUSE Linux 16.0, transactional updates are introduced in SUSE Linux 16.1 via its immutable version. This transition provides atomic, rollback-capable updates that ensure system resilience and business continuity.

SUSE Linux 16.1 ships with kernel version 6.12. The following kernel subsystems have been removed:

The following table provides an overview of the file system status in SUSE Linux 16:

In SLE 15, Kdump was configured through YaST. With YaST no longer available, use the kdumptool command-line tool. Configure Kdump via the following variables in /etc/sysconfig/kdump:

The kdumptool utility can check whether the running kernel has the expected crashkernel settings, update the boot loader configuration, and disable kdump by removing crashkernel settings from the boot loader.

SLE 15 used AppArmor by default and shipped SELinux without policies. SUSE Linux 16 makes a definitive switch:

For full details, see Understanding SELinux Basics.

Physical console login as root is unchanged. For SSH access, password-based root login is disabled by default. To re-enable it, install the openssh-server-config-rootlogin package. Key-based root login (via /root/.ssh/authorized_keys) continues to work.

In SLE 15, sudo prompted for the target user's password. SUSE Linux 16 tightens this:

This policy is implemented by the sudo-policy-wheel-auth-self package, which is installed by default on new SUSE Linux 16 systems.

YaST is not shipped in SUSE Linux 16. For interactive 1:1 management tasks, Cockpit provides a Web-based front-end. Note that Cockpit does not fully replace YaST some modules present in YaST are not yet available in Cockpit.

SUSE Linux 16 supports Ansible for automation. SUSE Multi-Linux Manager, which uses Salt internally, is also available for managing SUSE Linux 16 installations. Note that SUSE Linux 16 itself does not include Salt packages.

WBEM support (previously provided by SBLIM packages in SLE 15) has been dropped.

SUSE Linux 16 removes the module concept used in SLE 15 (base system, server applications, development packages, and so on). Separate pool and update channels are also gone. These changes, combined with Zypper improvements, deliver better update performance.

Minor releases (16.1, 16.2, and so on) continue to use separate repositories.