Sync ≠ Backup ≠ Archive

If you are just looking for the departmental backup system, you will find it here.

Red digits refer to more details below
Sync Backup Archive
I want it right here, right now.
  • it = the stuff you want to work on
  • here = your local disk on any machine you want to work with
  • now = at any time you want to work
Oops, I've lost it, how can I get it back? I want it to stay forever.
Consequence Delete it here, also gone there. Delete it here, can still get it there
within reasonable limits
Delete it here, guaranteed to get it there


if you know where to look and
within reasonable limits


Performance, Availability and Ease of Use
You want to
Disaster Recovery
You need to
Retention Policy
You have to
  • 3rd party (legal and archive issues?)


    • Google Drive, Dropbox, iCloud, Box, ...
  • Departmental/on-premise
    • Syncthing (available now, but complex?)
    • NextCloud (we are looking for a pilot project!)
  • scheduled rsync / unison / robocopy
    but what with sync-conflicts?
  • Using KU Leuven Tivoli:
  • Using some other reliable storage:


    • rsnapshot
    • Time Machine
    • CrashPlan
    • ...
Rarely automated because of lookup/index problem
  • rsync / unison / robocopy
    but what with sync-conflicts?
Risky (because you will forget)

Details and/or background

  1. Backing up your Files

    • You most probably want to keep your files/documents safe.
    • If you keep them in your departmental home directory or some other departemental server/directory, this is covered (more on that later)
    • If you keep them on your laptop or desktop (including system-group-administered laptops and desktops), you should do so yourself
    • Any (real) backup program is most probably OK
    • But not just any storage is OK (e.g. an external hard disk is not a reliable backup storage solution, but a Synology might be)
    • You need reliable storage - backup is only as good as the chance that you can get your data back when you need it
    • Backup is not the real problem, restore is the most important part
    • Backup needs to be automated, otherwise the thing you want/need will not be on your backup
    • If you cannot or do not want to take care of an automated, reliable backup on reliable storage, then you should/can:
      • consider Tivoli backup on your own laptop/desktop (not much used)
      • consider to sync your laptop/desktop to a server that is included in the departmental Tivoli backup (double win, see below)
  2. Syncing your Files

    • Syncing your files to your laptop/desktop enhances performance, availability and ease of use:
      • they are available from your local disk and also when being off-line
    • But Sync is not Backup:
      • If your sync is good (and it should be), then anything you delete or change, is also deleted/changed on any other sync-ed device
      • You cannot revert your changes with Sync alone
  3. Archiving up your Files

    • Backup is not Archive:
      • Backup has reasonable limits for performance and cost:
        • 60 days for versions
        • 365 days for deleted files
        • backup licenses are re-used if the machine is de-commissioned:
          • usually 1 to 2 years after its initial 5-year hardware support
          • when re-using a backup license, all existing backup data is deleted
      • Archive has different reasonable limits (only cost)
    • Archive is also usually not automated because of the indexing problem: no use putting it on archive if you cannot find it later on:
      • backup = live data, with live handles on where to start looking
      • archive = (long) deleted data, nothing remains to use as a handle/reminder
  4. Sync Solutions

    • If you need/want local files and you don't trust your own backup, then sync to a server and trust the backup of that server
    • 3rd party sync services might have legal/confidentiality issues (GDPR)
      • archiving that data might also be more complicated (e.g. what if the user/owner left)
    • departmental experiments
    • DIY in your home or some other server directory
  5. Alternatives for Sync

    • In case you don't want or can't have a (local) sync to get easy access to your files, you can consider some alternatives described with the storage options.
    • Not having your files on your local desktop/laptop has some advantages as well:
      • in case your laptop is stolen or lost, no valuable data is on it, so you need to worry less
      • when always working on the same (server-side) document, no sync conflicts can occur
      • security / access control is enforced at the server side so less local provisions have to be taken