Thayer Backups

All files on the ThayerFS and Jumbo file systems are backed up online to disk. Details of these backup methods are below:

Online Backups

Online backups of our file system are done automatically by our file system software using a technology called "Snapshots." These read-only snapshots of the state of all folders and files at a particular instant in time are taken on a fixed schedule and can be accessed easily during the retention period to recover either old versions of files or deleted files.

Limitations

One important caveat about the snapshot system is that the ability to retain snapshots is limited by the amount of disk space available on the volumes. For most volumes it is extremely unlikely, but if disk space were to begin to run out, the oldest snapshots would begin to be deleted until a pre-set amount of space was freed. This situation would not affect disk backups.

In the case of common, research and jumbo directories, the amount of snapshot space is limited to 20% of the directory quota - this additional space is provided above and beyond what is purchased. So, if large volumes of data are created and deleted repetitively in your directory, you may easily exceed the amount of space allocated to snapshots. Once the used snapshot space exceeds 98%, the oldest snapshots will be automatically deleted until the free snapshot space reaches 10%, resulting in fewer snapshot copies. Even in this case, the disk backups described below will not be affected, and Computing Services can retrieve backups if it is ever necessary.

Schedule

Currently, the schedule for our online backups is:

  • ThayerFS
    • Every two hours (e.g 2:00am, 4:00am, etc.) - up to the most recent twenty-two are retained
    • Every night at 12:00am - up to the most recent nine are retained
    • Every Sunday at 12:00am - up to the most recent fifteen are retained
  • Jumbo
    • Every night at 12:00am - up to the most recent fourteen are retained

How to retrieve backups

Retrieving backup data from Snapshots requires connecting to ThayerFS or Jumbo in a slightly different way than you may be used to. Please make sure to read and follow the instructions below closely.

Windows Previous Versions method (easy)

  1. Click on Start > Run... and type:
    \\thayerfs.thayer.dartmouth.edu
    	

    or

    \\jumbo.thayer.dartmouth.edu
    	

    A window will open containing a list of all folders on ThayerFS or Jumbo.

  2. Locate the folder that contains (or contained) the data you wish to restore, and double-click to open it up. For courses, find the folder for the specific term you need - for example, courses_12winter.
  3. Right-click on any file or folder, select Properties... and then click the Previous Versions tab.

    In this tab, you will see the dates and times of all the previous versions of the file or folder that exist. For example, a file that had not changed since the oldest snapshot will not have any previous versions since all the snapshots are newer than one week old.
  4. You can choose to either View, Copy or Restore one of the previous versions.
    • If you View a previous version of a file, it will open in it's associated application. Viewing a previous version of a folder will show you a view of what the folder looked like when the snapshot was taken. You can then select a file or files to copy out to another location.
    • If you select Copy, a complete copy of the previous file or folder will be copied to a location you choose.
    • If you select Restore, the previous version of the file or folder will completely replace the current version - use care with this option; it cannot be undone.

Windows Snapshot-folder access method (advanced)

  1. Click on Start > Run...and type:
    \\thayerfs.thayer.dartmouth.edu
    	

    or

    \\jumbo.thayer.dartmouth.edu
    	

    A window will open containing a list of all folders on ThayerFS or Jumbo.

  2. Locate the folder that contains (or contained) the data you wish to restore, and double-click to open it up. For courses, find the folder for the specific term you need - for example, courses_12winter.
  3. Find the ~snapshot (ThayerFS) or .zfs (Jumbo) folder at the root of the volume you have opened.
    • If you do not see a folder called ~snapshot or .zfs then you need to enable Windows to show hidden folders.
      1. From the Tools menu select Folder Options...
      2. Click on the View tab and select Show hidden files and folders
      3. Click the OK button to apply.
  4. ThayerFS: In the ~snapshot folder, you will find up to forty-six sub-folders:
    • hourly.0 through hourly.21 - these are the snapshots taken during the day, hourly.0 is the most recent. (Though these are named "hourly" they are created on the "Every two hours" schedule described above.)
    • nightly.0 through nightly.8 - these are the snapshots taken each night at midnight, nightly.0 is the most recent
    • weekly.0 through weekly.14 - these are the snapshots taken each Sunday at midnight, weekly.0 is the most recent

    Jumbo: In the .zfs\snapshot folder, you will find up to fifteen sub-folders:

    • GMT-YYYY.MM.DD-04.00.00 - these are the snapshots taken each night at midnight, identified by date
  5. To retrieve a file, simply copy it from the appropriate snapshot folder to a location outside the snapshot tree.

OS X

  1. From the Finder, select the Go menu and choose Connect to Server...
  2. Type in a server address like:
    smb://your_netid@thayerfs.thayer.dartmouth.edu/myfolder/~snapshot
    	

    or

    smb://your_netid@jumbo.thayer.dartmouth.edu/myfolder/.zfs/snapshot
    	

    where your_netid is your Dartmouth NetID and myfolder is the subfolder (under common, research, etc.) that you need to access. For your home folder, use your NetID as the folder name. For courses, the folder is the specific term you need -  for example, courses_12winter.

  3. Click the Connect button. If prompted, enter your Dartmouth password. This will mount the specified snapshot folder directly which you can then access from the Finder.
  4. ThayerFS: In the root of the volume you have just mounted, you will find up to fifty-six sub-folders:
    • hourly.0 through hourly.21 - these are the snapshots taken during the day, hourly.0 is the most recent. (Though these are named "hourly" they are created on the "Every two hours" schedule described above.)
    • nightly.0 through nightly.8 - these are the snapshots taken each night at midnight, nightly.0 is the most recent
    • weekly.0 through weekly.14 - these are the snapshots taken each Sunday at midnight, weekly.0 is the most recent

    Jumbo: In the root of the volume you have just mounted, you will find up to fifteen sub-folders:

    • GMT-YYYY.MM.DD-04.00.00 - these are the snapshots taken each night at midnight, identified by date
  5. To retrieve a file, simply copy it from the appropriate snapshot folder to a location outside the snapshot tree.

Linux Snapshots

Snapshots are available from linux clients, but are in a slightly different location. The snapshot directory is at the root of each ThayerFS folder as ".snapshot" or at the root of each Jumbo folder as ".zfs/snapshot". For home and courses, it is located at the root of the share, e.g. /thayerfs/home/.snapshot For common and research, it is located in the top-level directory, e.g. /thayerfs/common/abet/.snapshot   For courses, use the folder for the specific term you need, e.g. /thayerfs/courses/12winter/.snapshot

Within the snapshot directory are all the hourly and nightly snapshots described above, and within these are the same hierarchy as the main share or directory. So, for example, to find the "important" folder in the "secret" common folder that was captured in last night's snapshot, you would go to the directory: /thayerfs/common/secret/.snapshot/nightly.0/important

Home folders follow the same hierarchy as the top-level home share, so if your NetID is d12345x, you would find last night's snapshot of your home directory at: /thayerfs/home/.snapshot/nightly.0/d12345x

One potentially confusing thing about the snapshots on ThayerFS is that the modification dates of the folders do not reflect the times that the snapshots were taken. To see the actual snapshot times, you need to look at the access times. So, for example, to see the snapshot times for the "secret" common folder, you would use the following command:

ls -lu /thayerfs/common/secret/.snapshot/

Remote Backups (not user accessible)

Disk-based backups of our file servers happen every morning between midnight and noon.

At this time, there is no way for a user to retrieve a file or files from the offsite backups. If a file needs to be retrieved from these backups, please e-mail computing@thayer.dartmouth.edu with as much detail as possible (file name or names, file location(s), date(s) of file needed and/or deletion date of the file) and we will attempt to retrieve the file or files within one business day.

Backup Retention Policy

By policy, Computing Services does not retain backups for more than 200 days.

Still need help? Contact Us Contact Us