New O2 scratch filesystem /n/scratch replaces /n/scratch3

The /n/scratch3 filesystem is now read-only on the O2 cluster. It will be decommissioned and removed from O2 on Tuesday, January 16. 

There is a new O2 scratch space at /n/scratch which is replacing the old /n/scratch3 system. /n/scratch3 will be accessible until January 8, 2024, then read-only until January 16, 2024, when it will be fully decommissioned.

  • Please update any scripts or workflows that currently reference /n/scratch3 prior to January 16th.  
  • If needed, please copy any of your data off of /n/scratch3 as soon as possible prior to January 16th. HMS IT will not be migrating any data and no data will be recoverable from the old /n/scratch3 once it is decommissioned.  

The new /n/scratch system introduces several key changes: 

  • Increased storage – Each user now has a storage limit of 25 tebibytes (TiB), up from the previous 10 TiB. The file count limit is 2.5 million files per user. All data owned by the user counts toward this limit, regardless of the data location.  
  • Automatic file removal – To improve performance, files will now be automatically deleted 45 days after their last modification date, which is the last time a file’s content was updated. This is a change from the previous policy of 30 days after the last access time, which indicates the last time that a file was read or otherwise accessed.  
  • No backups or snapshots – This policy remains unchanged from the old /n/scratch3 system.  

To create your personal folder in the new /n/scratch, run this script from an O2 login server (not from an O2 compute node or transfer server): 

/n/cluster/bin/scratch_create_directory.sh 

This script will create a personal folder at /n/scratch/users/a/abc123, where abc123 represents your username. 

Please also see the O2 scratch documentation.

If you have questions or concerns, reach out to rchelp@hms.harvard.edu.  

IT Department