Stuart K' Paterson

1
Software Installation Using Pacman
Stuart K. Paterson
1
22/03/04
2

• Pacman A Package Manager

• What does Pacman do?
• Can transparently fetch, install, and manage
  software packages
• Handles dependencies
• Updates are automatically searched for
• Can recognise natively installed software
• Is very robust

• How does Pacman do this?
• Package 'tarballs' are kept in a central web
  based cache
• Each package has a corresponding '.pacman' file
  associated with it

Stuart K. Paterson
1
22/03/04
3

• Installation of Pacman

• Very simple procedure
• First download the appropriate tarball
• Untar and unzip this
• Source the appropriate setup file (.sh .csh and
  .ksh supported)

• Pacman can install itself
• Type- pacman -get Pacman
• Source the appropriate setup file
• Now Pacman can update itself when new versions
  are released
• Original installation can be removed

Stuart K. Paterson
1
22/03/04
4

• Test Case 1- Installation of CMT

• Structure of a typical .pacman file
• To install CMT, simply type pacman -get
  cmtv1r12t1

description'CMT v1r12 Test 2.00' suffixHandling0
download'''CMTv1r12t1.tar.gz' url'http
//www.ph.gla.ac.uk/stuart/' enviros
'pacname','CMT', 'installdir','lhcb/sw/cont
rib/CMT', 'tarball','CMTv1r12t1.tar.g
z'
Stuart K. Paterson
1
22/03/04
5

• Test Case 1- Installation of CMT

install'' 'echo Starting pacname
Installation...', 'mkdir -p installdir', 'cd
installdir tar -zxf PACMAN_INSTALLATION/
tarball', 'cd installdir/v1r12/mgr/
./INSTALL cd ../../ source pwd/v1r12/mgr/setu
p.sh cd v1r12/mgr/ echo Executing gmake...
gmake', 'echo End of pacname setup.'

Stuart K. Paterson
1
22/03/04
6

• How Pacman handles dependencies

depends 'cmtv1r12t1', 'aida-2-2-0'

• Recursive dependencies are dealt with
  automatically

A

• If package A depends on B and C
• With package B also depending on C
• Pacman knows only to install one version of C
  and to have it installed before A and B

B
C
C
Stuart K. Paterson
1
22/03/04
7

• Test Case 2 Gaudi v12r0 on Scotgrid

• Gaudi v12r0 depends on many packages
• AIDA pre-compiled
• Boost (which also depends on Python)
• CERNLIB pre-compiled
• CLHEP
• CMT
• GSL
• HTL pre-compiled
• Python
• Root
• Xerces-C
• Nag-C linked to existing
  version on Scotgrid

Stuart K. Paterson
1
22/03/04
8

• Test Case 2 Gaudi v12r0 on Scotgrid
  Installation

Stuart K. Paterson
1
22/03/04
9

• Test Case 2 Gaudi v12r0 Some Notes

• Total time taken was just under 2 hours, 21
  seconds of this was spent transferring tarballs
• Installation can be interrupted at any point and
  then restarted seamlessly
• Limitations exist due to Nag-C dependency and
  availability of pre-compiled packages such as
  CERNLIB, HTL AIDA
• More development time was spent learning how to
  install the packages from scratch than applying
  this knowledge to Pacman
• Another useful feature of Pacman is the automatic
  generation of an index page, accessible via
  pacman -info

Stuart K. Paterson
1
22/03/04
10

• Test Case 2 Gaudi v12r0 Sample Index Page

Stuart K. Paterson
1
22/03/04
11

• Other Pacman Features

• Recognising natively installed software

nativelyInstalled 'inpath''python',
'enviros''pythonroot', 'scripts''ch
eckok.sh'

• Need a uniform naming scheme to utilize this
  fully
• Cache manager
• Can handle rpm files as well as tarballs

Stuart K. Paterson
1
22/03/04
12

• Problems With Software Installation at External
  Institutes

• Little or no documentation
• No way of tracking changes to structure and
  setup from one package version to another
• Core software group extremely helpful but cannot
  be expected to answer a flood of queries
• The use of Pacman would remove these issues

Stuart K. Paterson
1
22/03/04
13

• Cache Management

• Suggest centrally managed cache with individual
  packages managed by those responsible and an
  overall cache manager
• Problems are solved once by the cache manager,
  leaving one point of contact when problems arise
  
• Cache manager has tight control over the
  structure of the software
• Easier to establish conventions
• Could be little to do, version to version
• Much time saved for others

Stuart K. Paterson
1
22/03/04
14

• Possible Use of Pacman for DC '04

• Modified versions of DaVinci could be
  transported to Tier sites
• Pre-compiled or otherwise
• Possibility of running trials on different
  platforms
• Durham (Fedora) and Liverpool (RH9) have been
  contacted
• Nodes without any software could become
  effective with Pacman
• Pacman can easily clean up after itself if
  necessary
• Updating package versions or applying patches
  for all institutions would become trivial

Stuart K. Paterson
1
22/03/04
15

• Conclusions

• Pacman is a very powerful tool which has no
  obvious drawbacks for LHCb
• Automation of packages is very simple for someone
  who knows how to do the installation
• Several advantages are presented by having a
  cache manager http
  //ppewww.ph.gla.ac.uk/stuart/

Stuart K. Paterson
1
22/03/04