SysLinuxOS 13.2 there was no more time

This release is not a simple update, but it is the “14” version that I had in mind, a real epochal change. There was no more time and I didn’t want to wait any longer.  SysLinuxOS  13.2 is a substantial revision of how the system handles storage, backups, recovery, and boot. The release introduces btrfs as the default filesystem and builds an integrated snapshot, rollback, and backup layer on top of it. All of these capabilities are preconfigured and active from the first boot, with no additional setup required.

btrfs by Default

New installations use btrfs with the standard @ subvolume for root and @home for home. Calamares performs the partitioning and subvolume layout automatically during guided installation, with no manual configuration.

btrfs enables capabilities that are not available on ext4: instant snapshots, full system rollback, and native incremental backups. In SysLinuxOS 13.2 these features are integrated and preconfigured out of the box.

Integrated Snapper Configuration

As soon as SysLinuxOS 13.2 is installed, Snapper is configured and active. The following operations are automatic:

• A baseline snapshot is created at the end of the installation, providing a clean reference point.
• Each apt install, upgrade, or remove operation creates a pre/post snapshot pair.
• Boot snapshots are created on each system start, before any service modifies files.
• A timeline retains daily, weekly, and monthly snapshots.

Retention limits are set to sensible defaults (NUMBER_LIMIT 5, TIMELINE_LIMIT_DAILY 7, GRUB_BTRFS_LIMIT 8). On upgrade, custom values set by the user are preserved.

GRUB Snapshot Menu and Rollback

Through grub-btrfs integration, a “SysLinuxOS — snapshots” submenu is added to the boot menu and updated on every update-grub, listing the most recent system snapshots.

To restore a previous state, boot a snapshot in read-only recovery mode and run syslinuxos-rollback. The tool renames the current @ to a timestamped backup, creates a new read-write @ from the selected snapshot, and recreates /.snapshots as an empty subvolume. After reboot the system returns to the selected state, with the full previous snapshot history preserved in the backup.

Multiple SysLinuxOS Installations on a Single Disk

btrfs and os-prober have a long-standing limitation, reported as a Debian bug and still open upstream (#921004, #940710): with two Linux installations on btrfs partitions, GRUB detects only the current one. The cause is that os-prober mounts the partition at the top level and looks for /etc/os-release there, while in the standard btrfs layout the file resides at /@/etc/os-release.

SysLinuxOS 13.2 addresses this with a custom, os-prober-independent solution. The script /etc/grub.d/13_syslinuxos-btrfs-otheros enumerates all btrfs partitions via lsblk, mounts each with subvol=@, checks for /etc/os-release, and generates complete GRUB menuentry blocks: a top-level entry with the most recent kernel, an “Advanced options” submenu listing all kernels newest-first, and a recovery entry. It runs alongside os-prober without conflicts, while os-prober continues to handle ext4/xfs installations. It can be disabled with a single line in /etc/default/grub.

In addition, /etc/grub.d/14_syslinuxos-snapshots-otheros detects btrfs installations that contain a grub-btrfs.cfg and generates a “SysLinuxOS — Snapshots of other installs” submenu that performs a direct configfile chainload into that installation’s snapshot menu. This allows booting the snapshots of another SysLinuxOS installation on the same disk.

SysLinuxOS Package Ecosystem

The btrfs, snapshot, clone, and backup functionality is delivered through four packages, each distributed as an installable .deb, independently versioned and tested.

syslinuxos-snapshots 0.3.9 — Snapshot Engine

This is the central package. Installing it provides the complete snapshot system, preconfigured and operational:

• syslinuxos-snapshots-setup — the Snapper setup script, with a --force argv bypass for execution inside the Calamares chroot, where the system D-Bus is unavailable and stock snapper fails silently. It uses --no-dbus to talk directly to the snapper library. The same logic applies in --reset-baseline mode, which removes spurious snapshots generated during installation and creates a single clean baseline (#1), using a retry loop and reverse-numeric sort to respect Snapper’s pre/post ordering constraints.
• syslinuxos-rollback — the rollback helper. It mounts the btrfs top level (subvolid=5), renames @ to @.rollback-bak-TIMESTAMP, creates a new read-write @ as a btrfs snapshot of the selected snapshot, and recreates /.snapshots as an empty subvolume. On reboot, fstab subvol=/@ loads the new root.
• /etc/grub.d/13_syslinuxos-btrfs-otheros and /etc/grub.d/14_syslinuxos-snapshots-otheros — the two GRUB scripts described above, packaged and installed automatically.
• Snapper configuration with set_if_default logic that updates only values the user has not changed.

grub-btrfs 4.14 — Snapshots in the Boot Menu

The grub-btrfs package bundled with SysLinuxOS is packaged and validated against the Debian @ / .snapshots layout. The “SysLinuxOS — snapshots” submenu updates automatically on every update-grub. Each Snapper snapshot is a bootable entry; the system starts in read-only recovery mode from that snapshot, ready for syslinuxos-rollback.

distroClone 1.4.8 — System Clone and Live ISO Build

distroClone builds a SysLinuxOS Live ISO from the running system, or clones the current installation to another disk. Version 1.4.8 is fully integrated with the btrfs ecosystem:

• btrfs-aware ISO build, with exclusion of .snapshots, @.rollback-bak-*, and var/lib/snapper/snapshots from the squashfs, so no source snapshot is carried into the installed target.
• Snapper setup inside the Calamares chroot via syslinuxos-snapshots-setup --force, using an argv-based bypass immune to environment-variable stripping between Calamares and its child processes. A persistent log is kept at /var/log/calamares-snapshots-setup.log.
• Baseline reset at first boot via remove-live-admin.service: after the Calamares and live-boot purges, a single clean #1 snapshot remains as the baseline.
• USB, QEMU, and VirtualBox commands include conv=fsync oflag=direct && sync in the final dialog, preventing non-bootable USB drives caused by unsynchronized write caches.

distroclone-backup 1.3.0 — Versioned Backups with Snapper

distroclone-backup extends the btrfs snapshot model to external-disk backups. In version 1.3.0 the operating mode adapts automatically to the destination filesystem:

• btrfs destination: the backup becomes a Snapper snapshot chain with a dedicated distroclone-backup config. The first backup creates the config and snapshot #1 (full baseline); each subsequent backup adds an incremental snapshot. Any version can be restored, in full or selectively.
• ext4, xfs, or other destination: classic rsync, with no change from previous versions.
• btrfs destination without Snapper configured: automatic fallback to raw btrfs snapshots (v1.2.2 compatibility).

Boot Improvements

• The Live session no longer stalls on the Samba NMB Daemon. In previous versions, boot could wait up to roughly 1m41s for an nmbd service with no available network interface. The nmbd.service and smbd.service units are now disabled in the build chroot before the squashfs is generated. SMB clients (gvfs, smbclient) continue to work normally.
• No Plymouth splash, for a more direct and transparent boot.

syslinuxos-install-extras

SysLinuxOS is built for IT professionals, system administrators, network engineers, and DevOps practitioners. Version 13.2 formalizes the bundled toolset with a two-tier approach.

TIER1 — Base Toolkit, Always Installed

Every SysLinuxOS 13.2 installation ships with a professional toolset out of the box:

• Networking and analysis: nmap, tshark, wireshark, tcpdump, mtr, iperf3, socat, netcat, bettercap, zenmap
• Firewall and security: nftables, iptables, ipset, fail2ban, rkhunter, chkrootkit, lynis, auditd
• VPN and connectivity: wireguard, openvpn, nginx, haproxy, keepalived
• Containers and orchestration: docker, docker-compose, kubectl, ansible, ansible-core
• Backup and storage: restic, borgbackup, rclone, rsync, lvm2, mdadm, cryptsetup
• CLI tools: git, python3, jq, yq, fzf, ripgrep, bat, tmux, htop, atop, glances

TIER2 — On-Demand Professional Stacks

Installing all specialized software by default would produce a multi-gigabyte ISO and a system running services most users do not need. syslinuxos-install-extras provides defined categories that install entire stacks with a single command:

sudo syslinuxos-install-extras networking   # DNS, DHCP, VPN, BGP/OSPF, HA, proxy, SNMP, IDS
sudo syslinuxos-install-extras devops       # monitoring, logging, containers, K8s, IaC
sudo syslinuxos-install-extras cloud        # AWS/Azure/GCP CLI, virtualization, storage, K8s
sudo syslinuxos-install-extras full         # all TIER2 in one operation
sudo syslinuxos-install-extras repos        # add official Grafana, HashiCorp, Helm APT repos

networking — for managing complex network infrastructures: authoritative and recursive DNS (bind9, unbound, dnsmasq, knot, nsd), enterprise DHCP (kea with DHCPv4/v6/DDNS), advanced VPNs (openvpn3, libreswan IKEv2, openconnect, ocserv, stunnel4, tinc), dynamic routing (FRR with BGP/OSPF/IS-IS/MPLS, bird3, exabgp, radvd), high availability (corosync, pacemaker, heartbeat, drbd), reverse proxy and web servers (caddy, lighttpd, squid, varnish), IDS/IPS (suricata, crowdsec), filesystem integrity (aide, tripwire), and enterprise authentication (freeradius, 389-ds, sssd with AD/Kerberos/LDAP).

devops — for building and monitoring production systems: the full Prometheus stack (prometheus, alertmanager, node-exporter, blackbox-exporter and related exporters), influxdb, classic monitoring (nagios4, icinga2, zabbix, collectd, munin, monit, cacti), advanced logging (rsyslog, syslog-ng, goaccess), container tooling (podman, buildah, skopeo), and IaC (ansible-lint, puppet-agent, cfengine3, terraform-switcher).

cloud — for distributed and hybrid infrastructures: official cloud CLIs (awscli, azure-cli, hcloud-cli, openstack-clients), a full virtualization stack (qemu-system-x86, libvirt, lxc, incus, vagrant), distributed storage (full ceph stack, glusterfs), I/O benchmarking (fio, bonnie++), and enterprise backup (bacula, amanda).

repos — before installing Grafana, Terraform, or Helm from official sources, this subcommand adds and signs the APT repositories for Grafana Labs, HashiCorp, and Helm, so subsequent installs come from the canonical source.

SysLinuxOS Repository

The four packages are already installable as .deb files. The next step is a dedicated, signed SysLinuxOS APT repository alongside the standard Debian repositories. With it, keeping the snapshot engine, clone tool, backup system, and grub-btrfs up to date becomes a standard apt upgrade, configured through a single entry in /etc/apt/sources.list.d/syslinuxos.list.

Testing

SysLinuxOS 13.2 has been tested on physical hardware in addition to virtual machines. Issues identified and resolved during testing include race conditions between services at first boot, silent Snapper failures inside the Calamares chroot, snapshot contamination between the source system and the installed target, and non-bootable USB drives caused by unsynchronized write caches. Each issue produced a specific, versioned fix.