MiniOS Session Manager

Utility suite for managing MiniOS persistent sessions from within the running system.

Numbered SquashFS sessions, persistence alert integration, save policies, and cross-component contracts are defined in the project checkpoint.

Components

• minios-session-manager - GTK3 GUI application
• minios-session - CLI for session operations

Usage

# GUI application
minios-session-manager

# Basic session management
minios-session list
minios-session create native
minios-session create luks 4GB
minios-session create squashfs --policy shutdown
minios-session create squashfs --policy manual --autosave 60
minios-session activate <id>
minios-session save <running-squashfs-id>
minios-session settings <squashfs-id> --shutdown on --autosave 60
minios-session delete <id>
minios-session cleanup --days 30
minios-session status

# Export and import sessions
minios-session export <id> output.tar.zst
minios-session import archive.tar.zst
minios-session import archive.tar.zst --force-mode dynfilefs
minios-session import archive.tar.zst --auto-convert

# Copy and convert sessions
minios-session copy <id>
minios-session copy <id> --to-mode raw --size 4GB
minios-session convert <id> dynfilefs --size 4GB

# Resize sessions
minios-session resize <id> 8GB

Session Modes

• native - Direct filesystem storage (ext2/ext3/ext4, Btrfs, XFS, etc.)
• dynfilefs - Expandable container files (works on any filesystem including FAT32/NTFS/exFAT)
• raw - Fixed-size image files (works on any filesystem including FAT32/NTFS/exFAT)
• luks - LUKS2-encrypted ext4 file (changes.luks), with no partition table or nested container
• squashfs - Exact compressed snapshots stored as a single changes.sb; creation captures the current live changes and activation selects the snapshot for the next boot

SquashFS can save automatically at shutdown (enabled by default) and can also save periodically every 30, 60, 120, 240, or 480 minutes. These settings are independent, and Save Now remains available at any time from the tray icon or Session Manager. Periodic saving increases CPU usage and storage writes because the current SquashFS implementation rebuilds the snapshot; one hour or longer is recommended. The 30-minute due check uses a systemd timer on systemd systems and a SysV worker on Devuan; both call the same minios-session autosave backend.

During the current unpack-to-RAM SquashFS mode, a newly captured and activated SquashFS snapshot can take ownership of the running session. Session Manager can then delete the old running snapshot without rebooting; other persistence modes remain protected from deletion while running.

All running-session SquashFS saves are delegated to the core MiniOS Tools minios-squashfs-save backend. It uses savechanges --profile exact, validates the captured snapshot, and atomically replaces changes.sb without retaining a rollback generation. The MiniOS core shutdown trigger calls the Tools backend, so automatic shutdown saving does not depend on Session Manager being installed and works with both systemd and SysV init.

copy always creates a new session. convert replaces the source by default; use --new-session to preserve it.

Filesystem Support

• POSIX filesystems - Native mode and available container modes
• FAT32/NTFS/exFAT - DynFileFS and raw containers; LUKS containers when cryptsetup, loop support, and the initrd LUKS hook are available
• SquashFS save currently requires a POSIX persistence filesystem because its private exact-capture staging must preserve links, ownership, modes, xattrs, ACLs, capabilities, and whiteouts. FAT32/NTFS/exFAT activation remains gated until a metadata-capable bounded workspace is implemented.
• DynFileFS, raw, and LUKS default to 4000 MB. CLI sizes accept decimal MB/GB/TB units up to 1 TB. Raw and LUKS are capped at 4000 MB on FAT32.
• Containers only grow; shrinking is unsupported.

Creating a LUKS session prompts twice for confirmation. Other operations that read or create LUKS data use --password-stdin; passphrases are never placed in arguments or metadata.

LUKS mode and --password-stdin are omitted from GUI and CLI choices unless /run/initramfs/etc/minios-initramfs-crypt, cryptsetup, and losetup are available in the running system.

LUKS exports contain decrypted logical session files, not the encrypted changes.luks container. Importing into LUKS creates a new encrypted container. Only .tar.zst imports are accepted; archive paths and file types are validated and extraction is bounded.

Build

make build
sudo make install

License

GPL-3.0+

Author

crims0n crims0n@minios.dev