1. The Home directory

The Home Directory (/home)

• The first type of storage is located in /home/[username] or ~/. This is a users home directory and it is Network File System (NFS) storage.
• All users have 100GB of space in their home directories. There is a hard quota on this and it cannot be increased.
• This directory is backed up! If a user accidentally deletes something or data gets corrupted, they should reach out to orcd-help-engaging@mit.edu for help.
• This space should be used for important files.
  

The Magic Backup

/home uses a snapshot technology that actually keeps mulitple versions of files and directories around.

There are 10x points in time that are captured as snapshots:

If the current time is 2021-01-12:30 (in 24 hour time, so 12:30 in the afternoon).

• hourly.2021-01-12_1205
• hourly.2021-01-12_1105
• hourly.2021-01-12_1005
  
• hourly.2021-01-12_0905
  
• hourly.2021-01-12_0805
  
• hourly.2021-01-12_0705
  
• daily.2021-01-12_0010
  
• daily.2021-01-11_0010
• weekly.2021-01-10_0015
• weekly.2021-01-03_0015

Every directory in /home has its own hidden .snapshot directory!

No matter what directory you are in, you can access the snapshot of the contents of that directory by going to .snapshot.

Let’s say a user is in /home/[username]/myproject/src and in that directory they just deleted the file “important_file.xml”. They can easily get it back from the most recent snapshot by running the command cp .snapshot/hourly.2019-11-12_1205/important_file.xml .

Users can also explore the .snapshot directories by cd’ing into them with cd .snapshot.

Remember that even though ls -la will usually show files and directories that start with “.”, .snapshot directories are a special case. Even though you cannot see them, they do exist!

If you have any questions or problems recovering files from .snapshot, please email orcd-help-engaging@mit.edu