Data Protection

Wharton’s user data space (/home and /data) are built on redundant, network attached storage, making it a reliable, safe place for you to store your data and code.

Snapshots

Our networked file systems include automated hourly and daily ‘snapshots’ of all user data space, providing our users with multiple user-accessible copies of all of their data. We snapshot:

  • hourly and always have the last four (4) hours available (we no longer offer hourly snapshots due to unacceptable performance cost)
  • daily and always have the last ten (10) days available
  • monthly and available until the next monthly snapshot is written

Backups

In addition to internal snapshots we also perform weekly traditional tape backups. These backup sets are rotated out of the tape systems after a period of time and sent to Penn archive storage for six months, after which the tapes are reused or destroyed.

Recovering Files

Depending on what you need to recover, there are two basic paths to file recovery in our environment.

Self Service

Most file recovery can be accomplished by you, the user, allowing for the fastest and most selective recovery.

Our snapshot system creates .snapshot directories in each departmental directory (/home/fnce, /home/hcmg, etc.). Because of the ‘.’ (dot), these files are hidden when you do an ‘ls‘ in the departmental directory. Trust us: they are there.

So to explore and recover files, log on to the HPCC with your ssh client, and ‘cd‘ into your departmental .snapshot directory:

That’s it! You may also be able to use an SFTP client to do recovery … remember the ‘.’ (dot), which will make the .snapshot directory invisible. Trust that it’s there!

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NOTE: Permissions in .snapshot directories are identical to those in your ‘normal’ directories. Only those with proper permissions can browse and restore your files.

Assisted Recovery (Tape)

If the Self Service method (above) isn’t adequate — generally if the files have been out of the user space for more than 10 days — please contact research-computing@wharton.upenn.edu with as much detail as you can provide. Path and name of files, and when the files were last in your user space are the most important details.

Tape recovery can take some time, as it generally requires requesting tapes from off site, loading, and (relatively) time-expensive scanning of tapes and writing them out. We thank you for your patience!

Other Methods

We recommend that you also use a Repository Service (Version Control) or Dropbox syncing to manage your code. Both of these methods provide the ability to recover multiple file versions, along with other valuable features.