Hardware

GM/CA CAT computing environment has identical structure for all three beamlines: 23-ID-D, 23-ID-B and BM. In order to provide better computing reliability and avoid heavy network traffic, each beamline is setup to have independent computing cluster running on a separated subnet. The structure of single cluster is shown on the picture below.

The core of the cluster is constituted by 8TB fiber-disk storage with 80MB/s data saving speed. This storage is placed on a 2Gb Storage Area Network and exported to client workstations via two servers while the data collection computer is connected to the SAN directly. Two groups of three workstations are provided. One is for user group currently collecting data and the other is for user group collected data on previous day and decided to stay for data post processing. These computers operate under Redhat Enterprise Linux operating system and have crystallographic data processing software installed including HKL200, PyMol, others. For details on crystallographic software please check User Program pages.

The following computing policies are implemented:

• The account management is centralized and all workstations access the same home directories that actually reside on the 8TB storage.
• No disk quota is enforced on user account.
• All workstations are provided with firewire or USB connectivity and users are encouraged to bring external firewire or USB disks for making data backups.
• Users can also FTP/SFTP out their data. At present there is no option to FTP/SFTP in due the ANL security restrictions.
• Users laptops are provided with 1Gb access to CAT network via RJ45 cable connection. The IP setup is automatically served by GM/CA CAT DHCP server. From this network users can access any workstation via SSH/SFTP and SAMBA. Besides, APS provides 54g wireless network in the GM/CA area. This wireless network allows to access outside Internet resources like web pages and e-mail, but not the GM/CA computers.
• User’s data will stored for two weeks from their experiment start date. During this period users are expected to verify that their backup was successful and data were safely delivered to their home institution. After two weeks an e-mail will be sent to remind users scheduled deleting of their data and then in two days the data will be automatically deleted from GM/CA storage.
• User accounts will be automatically disabled two weeks after their experiment start date.