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SDSC > User Support > Compute and Data Resource Guides > Resources: SAM-QFS User Guide

SAM-QFS User Guide


SAM-QFS at SDSC is a high-performance archival storage system for data collections. This system provides a complete data management system consisting of two integrated software products: SAM (Storage Archive Manager) and QFS (a high-performance, 64-bit, Solaris, SAN-based file system). Using SAM-QFS, users with data allocations may access data directly using a disk cache filesystem; the data then automatically migrates to tape.

There is no charge to XSEDE users for SAM-QFS and the limit to the number of files you may store is determined by your allocation. For information on obtaining a XSEDE allocation, visit the XSEDE Web site.

For special projects requiring long-term disk cache residency, contact SDSC Consulting.

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System Configuration

SAM-QFS has 16 tape drives, an 304-TB disk cache, and the following system configuration :

  • Meta Data Servers
    • 2 x Sun x4600
  • Data Login Servers
    • 2 x Sun v40z
    • 6 x 1GbE connections to the XSEDE/HPC network
  • Tape Drives
    • 16 STK 9940-B tape drives
    • 24 IBM J2 3592 tape drives

For a quick comparison of policies and recommended use between HPSS and SAM-QFS, please see Storage at SDSC: Quick Comparison.

warning It is your responsibility to back up critical data. This storage system is very reliable; however, data can be lost or damaged due to media failures, system software bugs, hardware failures, and user mistakes. Because of the enormous amount of data involved, SDSC maintains only one copy of SAM-QFS data on tape. For dual-copy capabilities or offsite backups, send a request to
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Logging In to the Data-login Node

Access the host via ssh. The command to log in as user is:

% ssh

Once you are logged in, you can find your files or data through the UNIX file system. Disk and/or tape allocations are located under /archive/science on the data-login node in a directory that will be named based on your username, project name, or project code. Store all data files in this directory.

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