How to check how much space your math account is using

Our current network file server capacity, divided by the number of accounts, leads to a limit of about 5 GiB per account. Of course, some accounts use little space, while others need more. New account holders may use up to 5 GiB without question. You may use an extra GiB for every year you have been affiliated with the department. Thus, for example, if you are a graduate student in your 4th year, you may use up to 8 GiB without question; if you are a faculty member and this is your 11th year here, you may use up to 15 GiB without question. We will update this page with new values as our server capacity increases.

Note: If you need more space for legitimate research-related purposes, you may temporarily use double the limit from the previous paragraph without first contacting us, but we may contact you for justification if we are observing a strain on the system. If you need more than double the previous paragraph's limit, even temporarily, or need to exceed the previous paragraph's limit on a more permanent basis, you must consult with us before swelling your account. Because there is at present no system-enforced quota, your actions can negatively impact other users, possibly the department as a whole.

Determine current usage and identify large files

To determine your current usage, or to find the files that are taking up the most space, you will first need to use SSH to connect to Once you are logged in, you can use the following commands:

  • Determine overall usage: du -sh ~
  • Identify large items in current directory: du -s .* * | sort -n
  • Delete a file: rm filename
  • Change to subdirectory: cd subdirectoryname
  • Change to parent directory: cd ..
  • Remove an empty subdirectory: rmdir subdirectoryname
  • Start over in home directory: cd ~

Use local hard drive scratch space for large files and faster access

If you are using a department Linux computer, there is typically 100 GiB of space available on your computer's local hard drive in the directory "/scratch/username". You may create subdirectories and store files there. Note that these files are not stored on our file server and thus not backed up automatically. Additionally, since these files are stored locally, they do not contribute to the data quota above.  Also, they are local to that particular computer, meaning: if you log in on a different computer (in, say, the 369/385 lab), there is a different scratch space there. On the other hand, your computer can access the local scratch space significantly faster than the network file server. The scratch space is a great choice for large data files being generated by computation programs, or other files that do not fit in your network account. You can manually back up your scratch space by using an external hard drive (see below).

Alternatives if you need more space than we can offer

Cloud-based services (such as DropBox, Google Drive, Microsoft SkyDrive, Amazon CloudDrive) often provide around 5 GB for free, or more for a reasonable fee. To store large file collections such as your music and photo and video collections, please consider purchasing a portable (USB-powered) hard drive---giving you around 1.5 TB for about $100.