At IU, what is the Libra Cluster?

On this page:

• Introduction
• Hardware configuration
• Networking
• Storage
• Getting a Libra account
• More information

Introduction

The Libra system at Indiana University is a cluster of three IBM BladeCenters and seven IBM p575s all running AIX 5.3. IU faculty and sponsored graduate and undergraduate students and staff may use Libra. The Power chips in the p575s and the Blades can attain up to four floating point operations per cycle, providing extremely high throughput for scientific workloads. Libra became available in August 2005, and continues a tradition of providing central IBM AIX systems for IU research computing needs since 1992.

The p575 nodes libra43, libra47, libra48, libra49, and libra50 are dedicated to large-memory serial applications and to shared-memory multiprocessor (SMP) applications requiring up to eight CPUs. Serial applications and two-CPU SMP applications requiring less than 4GB of memory run on the Blade nodes, libra01-libra42. The p575 nodes libra45 and libra46 are dedicated to research databases (the Research Database Complex, RDC).

Two of the Libra Cluster nodes are accessible via SSH clients: libra01 and libra02, both in the domain uits.iu.edu.

Hardware configuration

• IBM BladeCenters (3):
  
  
  • 14 JS20 Blades
  • 2 x 2.2GHz dual-core PowerPC 970FX processors per Blade
  • 4GB memory per Blade
  • 2 x 36GB SAS disk per Blade

• IBM p575 (7):
  
  
  • 8 x 1.9GHz Power5 processors
  • 2 x 146GB SAS disks
  • 16GB memory (libra43)
  • 32GB memory (libra47, libra48, libra49, libra50)
  • 64GB memory (libra45 and libra46 [database])

Networking

Each Blade chassis has four gigabit-Ethernet connections to a Force10 switch that connects to the other research systems. Fourteen JS20 Blades, each with gigabit-Ethernet adapters, share those four connections. The larger SMP p575 nodes each have their own dedicated gigabit-Ethernet connection to a Force10 switch.

Storage

User home directories reside on the IBM N5500 NAS storage device with disk quotas of 10GB per user. Note that your quota will be shared by your Big Red, Quarry, and RDC accounts, if you have accounts on those systems. If you need additional disk space, email the High Performance Systems group. The Massive Data Storage Service (MDSS) is also available if you need more storage.

Each Libra node has 10GB of local scratch space. Shared scratch space is provided as two 2TB file systems residing on the EMC NAS, /shscr1 and /shscr2. Files more than 90 days old will be automatically deleted to free up space there.

Getting a Libra account

To obtain an account on Libra, use the Account Management Service (AMS):

1. Visit the AMS at: https://itaccounts.iu.edu/
2. Select Manage my IU computing accounts.
3. If you are prompted to log into the Central Authentication Service , enter your Network ID username and passphrase. If not, skip to the next step.
4. Click create more accounts.
5. Use the radio buttons to select the account you want to create, and then click Create Account.

More information

For more about Libra, see the Libra home page.

Libra is supported by the UITS High Performance Systems group. If you have questions about Libra, email High Performance Systems. If you have questions about compilers, programming, scientific/numerical libraries, or debuggers, email the High Performance Applications team. If you have questions about statistical and mathematical software, email the Stat/Math Center.

Also see:

• Where can I get help using IU's supercomputers?
• At IU, what research computing services are available?
• Using LoadLeveler on Libra at IU
• Getting started on Libra
• Policies regarding UITS research systems