Container & Persistence

Container

SyncOS as an OS host contains a set of lxc containers within the OS. Internet capable applications are put into different LXC containers.

Publicly published SyncOS has the following containers:

  • LXC Email_Container: container for Thunderbird email client.
  • LXC App_Container: for own installed 3rd party applications.

Application in one container cannot access files of another container. Application in containers cannot see file system of host OS.

SyncOS by default contains the Email_Container LXC container. It shares with the SyncOS host OS for the same storage and uses the same access method. Typical file access is not persistent except for account and profile settings. Email storage folder should use Rclone cloud mapped folder.

App_Container LXC container is different. By default SyncOS doesn't contain it. For its installation, customer needs to copy 5600MB or 12600MB version App_Container_disk.img to the USB drive. Once copied, it can be used.

The App_Container is a guest desktop OS which is also forked from Debian Stretch distro.

You can refer to LXC web site for more details about LXC technology.

Persistence Storage

SyncOS Live USB uses an disk block device image file User_Home_disk.img as OS persistent storage. The OS file system filesystem.squashfs from within SyncOS-Live-yyyymmddx.iso is a read-only file system, and could not be altered. This User_Home_disk.img is a mandatory file to make SyncOS work and to keep some settings and profiles persistent.

After SyncOS boot up, User_Home_disk.img will be mapped as teleon user's home folder. Those important data which need persistent storage are symlinked into this teleon home folder, including wifi setting folder, ssh setting folder, desktop icon settings, as well as application's profile data in the email LXC container.

In Live USB, only two files could be changed during daily operations: User_Home_disk.img file for SyncOS settings, and App_Container_disk.img file for 3rd party application container (optional). All other files on Live USB are read-only and couldn't be altered. If you change some content of those files, the changes are only done in memory under current session. Once rebooted, they will be reloaded and resumed to original content.

Persistent file User_Home_disk.img need to be backed up routinely. A corrupt User_Home_disk.img may impact SyncOS boot up. If this were the case, restoring it can be done easily by copying back your last backup file.

In your daily work, if you find some operations need to save the setting data for next work session use, please kindly inform Teleon, so we can move its folder into the persistence in next SyncOS release.