Scientific Linux Experience at RHIC Computing Facility

1
Scientific Linux Experience at RHIC Computing
Facility

• Christopher Hollowell
• Physics Department
• Brookhaven National Laboratory
• hollowec_at_bnl.gov

2
Red Hat Linux End Of Life Options

• Red Hat Enterprise Linux
• Not cost effective when installed on a 2800 CPU
  farm
• Debian, SuSE, Mandrake
• Require change in automatic installation
  mechanism
• Support for third party applications (PGI
  Compilers, TotalView, etc.) questionable
• Fedora Core
• Short support periods (1.5 years including
  Fedora Legacy support)
• Third party application support concerns
• Uncertainty over stability

3
Red Hat Linux End Of Life Options (Cont.)

• Scientific Linux
• In use at several HEP/NP sites
• No cost
• Requires few changes to RCF's current
  installation/custom package management model
• Built from RHEL3 sources --gt compatibility with
  Enterprise --gt few third party application
  support concerns

4
Scientific Linux Usage at RCF

• Upgrade of CAS/CRS farm to SL 3.0.2 (updates) in
  progress
• Some bugs encountered which are also present in
  RHEL3
• ACL issue when mounting VxFS filesystems via NFS
  from servers running Solaris 8/9 RH Bugzilla Bug
  106584. Built a custom mount package to resolve
  this issue
• Symbolic links created on ext3 filesystems at
  installation time (under BOOT kernel) have their
  mode bits set to 755 RH Bugzilla Bug 116317,
  seemingly benign

5
Scientific Linux Usage at RCF (Cont.)

• Problems debugging processes which often call
  fork() or system() with gdb (6.1post-1.20040607.17
  rh)

Try debugging include ltstdio.hgt int
main() printf(gdb test\n) while(1)
if(!fork()) exit(1) sleep(1)
You'll receive several Detaching after fork from
child process messages, and gdb will become
suspended shortly thereafter (seemingly via
SIGTTOU). After placing gdb in the foreground,
you'll repeatedly get the gdb pager
prompt. Workaround 'set height 0'
6
Scientific Linux Usage at RCF (Cont.)

• Successfully tested several proprietary packages
• PGI Workstation 5.1-6
• TotalView 6.5.0
• LSF 5.1
• Condor 6.6.6
• Intel C/C and Fortran Compiler suites v8.0
• Haven't tried customization with the sites
  feature manually integrating updates/custom
  packages into tree (as we have done in the past)
  for now
• Build environment in place which allows us to
  build SRPM updates directly from Red Hat if
  necessary
• Overall impression quality distribution