AliceBox

A discussion on setting up the ALICE VOBox at Birmingham.

Introduction

The aim is to configure our grid resources at Birmingham to allow ALICE production jobs to run. The intention is to eventually support user analysis jobs as well. Instructions on how to setup a generic VOBox are available on the GOC Twiki, and specific instructions for ALICE are available on the AliEn Twiki.

Alice require a Cream CE and a VOBox, both of which need to be 64bit machines. This will follow shortly.

VOBox Installation

Machine Installation

The VOBox has been deployed as a 64 bit virtual machine running SL 5.3. It has the name epgr03.ph.bham.ac.uk and the DN epgr03.ph.bham.ac.uk/emailAddress=lcg-site-admin@hep.ph.bham.ac.uk. The machine is configured using cfengine (known as the class alice_vobox, with configuration files stored in the repo/alice_vobox on epgmo1). The command yum -y update was issued before any further installation commenced.

The machine has been configured to use ntpd.

gLite Installation

Installation proceed by first downloading the lcg-CA and glite-VOBOX yum repo config files. The repos sl-contrib, sl-srpms and dag were also enabled.

The packages lcg-CA and lcg-VOBOX were installed using yum. alpine and zsh were also installed as standard.

Firewall settings

In addition to the normal Birmingham-enabled ports (ssh, cfengine etc), the following ports have been enabled:

Port	Function	Restricted to
1975	GSISSH	Global
2170	BDII	Global
2811	GridFTP?	Global
20000-25000	Globus TCP Port Range	Global

Software Areas

Only the ALICE local cluster software area is available at the moment, NFS mounted to epgr03:/egee/soft/alice. NOTE! This area is owned by sgmali01:alicesgm on epgsr1, and this user does not exist on epgr03!

Yaim Configuration

Users

Only one user has been configured on the VOBox:

• yaim-conf/users.conf

        1001:alicesgm:1002,1000:alicesgm,alice:alice:sgm:
  

• yaim-conf/groups.conf

        "/VO=alice/GROUP=/alice/ROLE=lcgadmin":::sgm:
        "/VO=alice/GROUP=/alice/ROLE=production":::prd:
        "/VO=alice/GROUP=/alice"::::
  

Online the vo.d/alice config file has been transferred to the VOBox by cfengine.

Backup Policy

This node is not currently backed up. This will be reviewed in the New Year.

Testing

Port Availability

Tested with telnet (ie telnet epgr03.ph.bham.ac.uk 1975 etc). Comparing with port availability on vobox.egee.cesga.es.

Port	Example Box	Bham Box
1975
2811

GSISSH

1. Edit /etc/grid-security/grid-mapfile and map DN to alicesgm (ie add line "/C=UK/O=eScience/OU=Birmingham/L=ParticlePhysics/CN=christopher curtis" alicesgm)
2. Log onto node using gsissh: gsissh -p 1975 epgr03.ph.bham.ac.uk
3. $X509_USER_PROXY variable should be set after successful log in.

GridFTP?

The command edg-gridftp-ls gsiftp://epgr03.ph.bham.ac.uk/tmp may be used to check the globus-gridftp service is running.

Site BDII

The VOBox has been entered into the site BDII information by adding the line:

BDII_VOBOX_URL="ldap://epgr03.ph.bham.ac.uk:2170/mds-vo-name=resource,o=grid"

to the site_bdii/site-info.def file. Yaim has been re-run on the site BDII.

Storage Element

ALICE require xrootd to be installed on the Storage Element.

-- ChristopherCurtis - 29 Jul 2009