Quattor installation and use feedback from CNAF/T1 LCG Operation Workshop 25 may 2005 Andrea Chierici – INFN CNAF

25 may 2005Andrea Chierici - CNAF/T12 Introduction Location: INFN-CNAF, Bologna (Italy) Computing facility for INFN HNEP community –Partecipating to LCG, EGEE, INFNGRID projects Multi-Experiment TIER1 –LHC experiments –VIRGO –CDF –BABAR –AMS, MAGIC, ARGO,...

25 may 2005Andrea Chierici - CNAF/T13 Computing facility 800 linux boxes with different hardware –Cpus: PIII, xeon, opteron –HDs: scsi, eide, sata (connected in many ways) –OSs: redhat 7.3 (phasing out), SLC Different targets –LCG farm –Babar and CDF own farms Special requirements

25 may 2005Andrea Chierici - CNAF/T14 Looking for an installation tool All this heterogeneity requires a robust installation tool –DataGrid collaboration produced lcfg as an interim solution –Quattor is the final product of WP4 effort Took the basic ideas from lcfg Improved architecture Reliable Supported mainly by CERN and somehow by other sites (LAL, NIKHEF, CNAF, …)

25 may 2005Andrea Chierici - CNAF/T15 Quattor within Since release 1.0.0, this is the one and only tool used to install new nodes –Used different “layers” of installation: Vanilla for general purpose nodes (e.g. babar nodes) Quattor-gdb for lcg machines (LCG CE, WN, UI, etc) Soon: support for different hw architectures (i386, x86_64)

25 may 2005Andrea Chierici - CNAF/T16 Components used grub nfs ldconf accounts authconfig afs ntp chkconfig altlogrotate globuscfg cmnconfig rm dirperm filecopy profile edglcg rgmaclient gridmapdir

25 may 2005Andrea Chierici - CNAF/T17 Advantages After a slow start phase, now fully in production Easily portable to different OS versions (rpm based) All nodes install with kickstart, no hw support problem (compared to lcfg) Idempotent node configuration –We are sure the configuration is exactly the one we want (compared to lcfg) Very robust and scalable (by its architecture), based on standard protocols and programming languages (http, tftp, dhcp, xml, perl)

25 may 2005Andrea Chierici - CNAF/T18 What is missing Kickstart generation is incomplete –Partitioning is hard-coded –Impossible to specify ad hoc post-installation script Organization of templates in subdirectories –Hundreds of templates to manage –Something done by Cal, but not included in standard release (subversion based)

25 may 2005Andrea Chierici - CNAF/T19 Problems (1) Best effort development and support Version outdated, several improvements done, required a new tag Very slow to compile many templates –More than 2 hours to upgrade the 600 nodes of the LCG farm now managed (even to add a single rpm) Already fixed (now it takes just some minutes) Quite hard to “grasp” –Documentation clear but not sufficient –Development of new components requires OO perl

25 may 2005Andrea Chierici - CNAF/T110 Problems (2) LCG does not support quattor directly For LCG deployment we depend on Cal –If he wins the lottery, right now no one is able to take over his job –yaim is the only “blessed” tool by LCG CERN uses yaim on quattor We did not like the mixed solution and decided to use Cal’s release (always possible to change) –Experiencing some problems with VOMS and GridICE configuration

25 may 2005Andrea Chierici - CNAF/T111 Man power required Currently 1 FTE to manage all the installations Starting phase quite hard –Learn a little of pan –Understand the templates structure When in production, depending on the updates required, may require less effort

25 may 2005Andrea Chierici - CNAF/T112 Conclusions Quattor rocks The TOOL used on our farms –Immediately integrated in our pre-existing installation infrastructure (based on lcfg) –Can be implemented with just 1 server –Suggested when the number of nodes goes over 50 units or when dealing with different farms Some concerns about the future –LCG –Glite –Generic support “CERN-dependent”