At IU, what is the Data Capacitor?

On this page:

• Overview
• Hardware
• Project space
• Requesting an allocation for your project
• Scratch space
• Accessing the Data Capacitor
• More information

Overview

The Data Capacitor is a high-speed, high-bandwidth storage system for research computing that serves all Indiana University campuses and TeraGrid users. At peak performance, the Data Capacitor has a 14.5GB per second aggregate transfer rate.

The Data Capacitor provides high read/write speeds for user data and support for very large files. Using a wide area file system, the Data Capacitor permits users to access remote data as if the file system were mounted locally, allowing you to share large amounts of data with researchers at multiple remote sites. Data Capacitor file space is divided into two categories: project space and scratch space.

The Data Capacitor is not intended for long term storage of data, and is not backed up. You can archive data stored or created on the Data Capacitor on IU's HPSS using, for example, HSI or any of the other methods used to access HPSS (see How do I access IU's MDSS/HPSS from my TeraGrid account?). It is your responsibility to arrange for long term storage of any data on the system as needed.

Hardware

The Data Capacitor consists of:

• 52 Dell servers running Red Hat Enterprise Linux
• 24 Myricom 10-gigabit Ethernet cards
• 12 DataDirect Networks S2A9550 storage controllers
• 30 DataDirect Networks 48-bay SATA disk chassis
• 535TB usable disk storage using the Lustre file system
• 6 water-cooled Rittal racks with magnetic locks

Project space

The Data Capacitor projects directory is dedicated to long-term projects with storage requirements that cannot be met with other existing systems.

The entire system contains up to 524TB of shared space. The default size for project requests will be 10TB. (See the instructions below for requesting an allocation. If you need more than 10TB of space, you must submit a written request, which the Data Capacitor Allocation Committee will review.) Due to performance issues, UITS discourages storing a large number of small files, but will discuss arrangements if you need to do this.

Files in project space older than 30 days may be purged.

Requesting an allocation for your project

You may submit a request for project space to Team Data Capacitor; the Data Capacitor Allocation Committee will evaluate your application. To request project space, fill out and submit the Allocation Request Form. Your request must include:

• Project proposal and justification
• Project participants
• TB requested
• Data rate required
• Special requests (e.g., additional mounts)
• Directory name for the project space (e.g., /N/dc/projects/project_name)

When you submit the form, it goes to the PIs on the Data Capacitor grant, who will approve or deny your request. If you have questions about your request, contact the Data Capacitor team at  dc-team-l@indiana.edu .

Scratch space

The Data Capacitor scratch directory is a temporary workspace available to all Big Red and Quarry users. Scratch space is not allocated and its total capacity will fluctuate based on project space requirements.

Files in scratch space may be purged after 14 days.

Accessing the Data Capacitor

The Data Capacitor is mounted on Big Red and Quarry as /N/dc/..., where it behaves like any other disk device. If you have an account on Big Red or Quarry, you can access /N/dc/scratch. Access to /N/dc/projects requires an allocation, as described above.

More information

For more, see the Data Capacitor home page.

This document was developed with support from the National Science Foundation (NSF) under Grant No. 0503697 to the University of Chicago and subcontracted to Indiana University. Additional support was provided by IU through its participation in the TeraGrid, which is supported by the NSF under Grants No. 0833618, SCI451237, SCI535258, and SCI504075. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF.