HPSS User Forum, Santa Fe

1
History

• Test system HPSS 3.2 installation in Oct 1997
• IBM AIX machines with IBM 3590 drives
• Port of mover to Digital Unix then started
• mostly functionality testing, no unexpected
  problems/delays
• API - simple slow, or complex fast
  sequential, needs application changes
• Modified existing CERN RFIO interface to use fast
  HPSS interface to profit from existing investment
• Services started August 98 using HPSS 3.2

2
CERN files - where do they go?

• AFS small files up to 20MB
• home directories and some project files
• HPSS medium sized files gt 20 MB, lt 10 GB
• used to be on user-managed tapes!
• rfcp local-file hpsssrv1/hpss/cern.ch/user/l/lo
  ginid/hpss-file
• stagein -M /hpss/cern.ch/user/l/login/hpss-file
  link-file
• hsm -x get /hpss/cern.ch/user/l/login/hpss-file
  local-file
• Transparent to Objectivity DB users using
  modified SLAC AMS/HPSS interface
• HPSS Data taking for some experiments and test
  beams
• performance and reliability are very important
• files often go into the wrong COS

3
Production hardware HPSS 3.2

• IBM F50 RS/6000 main server (ns, bfs, etc.)
• 512 MB RAM, 2 cpus, AIX 4.2.1.0
• Fastethernet
• 2 IBM F50 RS/6000, disk tape server
• 256 MB RAM, 2 cpus, AIX 4.2.1.0
• 2 IBM 3590 drives, 10 GB cartridges
• 4 x 7 x 18 GB disks mirrored
• 344 GB total space in HPSS storage class 1
• 114 GB total space in HPSS storage class 4 (2
  tape copies)
• HIPPI Gigabit
• 2 COMPAQ Alpha 4100, disk tape server
• 512 MB RAM, 4 cpus, Digital unix 4.0D
• 2 STK Redwood drives, 10GB, 25GB, 50B cartridges
• 2 x 7 x 18 GB disks mirrored
• 240 GB total space in HPSS storage class 2
• HIPPI Gigabit

4
HPSS1D02
IBM RS/6000 F50
HPSS disk tape Mover
Hippi
Gigabit
Hippi
Gigabit
HPSSSRV1
Client
Fast Ethernet
Fast Ethernet
IBM RS/6000 F50
Any Platform
Network
Hippi
Chorus, NA57, etc...
HPSS server
Gigabit
Gigabit
Gigabit
Hippi
Hippi
SHD56
SHD55
DEC AlphaServer 4100
DEC AlphaServer 4100
HPSS disk tape Mover
HPSS disk tape Mover
5
HPSS Performance
HIPPI
25 MB/s
6
Data currently in HPSS at CERN

• Mixed sized files
• 1 TB, 15000 files, 60MB average
• Raw Experimental Data and Test Beam Files
• NA57 raw data 2 TB, 3000 files (to be repeated)
• Atlas Objectivity test data 1 TB in 2000 files
  (to be repeated)
• CMS 700 GB, 5000 test beam files, 140 MB average
• sometimes 3 TB in one day
• Total
• 10 TB, 65000 files, 100-800 tape mounts / day

7
Current and Future Work

• Ongoing work with HPSS
• ALICE data challenge largely successful, will be
  repeated
• test scalability of the name space to several
  million files
• upgrade to 4.1.1 for new function Y2K when
  Encina TX arrives!
• Successful service but too soon to commit to
  HPSS
• Complete COMPAQ port now underway - and Solaris
  port coming
• BABAR started with HPSS Objectivity so we will
  learn from them
• CERN stager enhancement program (CASTOR) well
  under way
• Will run HPSS till end 2000 with modest expansion
  and some stress testing to complete evaluation
• Limited volume of real data in HPSS could be
  exported to another system if final decision is
  to stop HPSS

8
HPSS Wish List

• Short Term
• Encina TX series 4.2, so can move/port to HPSS
  4.1.1
• Better monitoring information - help with Redwood
  problems
• New changecos option helps, but other
  improvements needed
• Long Term
• Non-DCE movers
• Movers running on Linux
• Improved random access and small-file migration
  performance
• Guaranteed input rate
• ways to avoid disk contention problems
• number of tape drives dedicated to a COS
• avoid stopping PVL etc. to change configuration
• multiple HPSS systems on same license