1. LFC Server Installation & Configuration
Giuseppe La Rocca
INFN – Catania
gLite Tutorial
Rome, April 2006

2. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
Outline
Introduction to LCG File Catalogue (LFC)
How to install a LFC Server
LFC References
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

3. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
File Catalog Motivations
User and programs produce and require data
Data may be stored in Grid datasets (files)
Located in Storage Elements (SEs)
Several replicas of one file in different sites
Accessible by Grid users and applications from “anywhere”
Locatable by the WMS (data requirements in JDL)
Data may be copied from/to local filesystems (WNs, UIs) to the Grid
Why File Catalogs are used?
They keep track of the location of copies (replicas) of Grid files
They provide DM tools and APIs through which users and grid services can deal with files
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

4. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
Name conventions
Name conventions
Logical File Name (LFN)
An alias created by a user to refer to some item of data, e.g. “lfn:cms/ /run2/track1”
Globally Unique Identifier (GUID)
A non-human-readable unique identifier for an item of data, e.g.
“guid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6”
Site URL (SURL) (or Physical File Name (PFN) or Site FN)
The location of an actual piece of data on a storage system, e.g. “srm://pcrd24.cern.ch/flatfiles/cms/output10_1” (SRM) “sfn://lxshare0209.cern.ch/data/alice/ntuples.dat” (Classic SE)
Transport URL (TURL)
a valid URI with the necessary information to access a file in a SE, e.g.“rfio://lxshare0209.cern.ch//data/alice/ntuples.dat”
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

5. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
The LFC
The LFC
LFC features
Hierarchical namespace for LFNs
Integrated GSI Authentication + Authorization
Access Control Lists (Unix Permissions and POSIX ACLs)
LFN acts as main key in the database. It has:
Symbolic links to it
Unique Identifier (GUID)
System metadata
Information on replicas
One field of user metadata
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

6. LFC Server Installation
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

7. Installation Pre-requisites
Start from a fresh install of SLC 3.0.x
Verify that apt is installed and properly configured:
rpm -qa | grep apt
Install apt if necessary:
rpm -ivh
Java SDK is required to install almost any LCG/gLite grid service. Due to license issues, it is not found in the LCG repositories. So please download and install a release of Sun Java SDK >= 1.4.2_08 from
chmod +x j2sdk-1_4_2_10-linux-i586-rpm.bin
./j2sdk-1_4_2_10-linux-i586-rpm.bin
rpm -ivh j2sdk-1_4_2_10-linux-i586.rpm
Preparing ########################################### [100%]
1:j2sdk ########################################### [100%]
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

8. Security pre-requisites
Request a X509 host certificate for the LFC Server you are going to install from a Certification Autority (CA). For example, to get host certificates from the GILDA CA, go to:
Install host certificates (hostcert.pem and hostkey.pem) in /etc/grid-security.
chmod 644 hostcert.pem
chmod 400 hostkey.pem
If you plan to use certificates released by unsupported EGEE CA’s, be sure that their public key, signing policy and CRLs (usually distributed with an rpm) are installed in /etc/grid-security/certificates.
For the VO GILDA, the RPM is available from
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

9. Node Syncronization with NTP
Syncronization among all LCG nodes is mandatory. It can be achieved by the NTP protocol and a time server
Install ntp if not already available for your system:
apt-get install ntp
Add your time server in /etc/ntp.conf
restrict <time_server_IP_address> mask nomodify notrap noquery
server <time_server_name>
(you can use ntp-1.infn.it – IP )
Edit /etc/ntp/step-tickers adding your(s) time server(s) hostname
If you are running a firewall, you will have to allow inbound comminication on the NTP port:
-A INPUT -s <NTP-serverIP-1> -p udp --dport 123 -j ACCEPT (add in /etc/sysconfig/iptables)
Activate the ntpd service with the following commands:
ntpdate <your ntp server name>
service ntpd start
chkconfig ntpd on
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

10. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
YAIM Installation
YAIM is a set of bash scripts used to install and easily configure the LCG middleware on the target machine
Ensure you FQDN is properly set
hostname –f
Find the latest YAIM version at
Download it using wget
wget
Install using
rpm -ivh lcg-yaim noarch.rpm
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

11. Site Configuration File
All the configuration values to sites have to be configured in a site configuration file using key-value pairs.
This file is shared among all the different LCG node types. So edit once and keep it in a safe place
Create a copy of /opt/lcg/yaim/examples/site-info.def template (coming from the lcg-yaim RPM) to your reference directory for the installation (e.g. /root):
cp /opt/lcg/yaim/examples/site-info.def /root/my-site-info.def
The general syntax of the file is a sequence of bash-like assignments of variables (<variable>=<value>, no spaces are allowed around =).
A good syntax test for your site configuration file is to try to source it manually running the command:
source my-site-info.def
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

12. LFC Server related variables
$MY_DOMAIN -> your domain
$LFC_HOST -> the hostname where the LFC will be installed
$LFC_DB_PASSWORD -> the Mysql password for the "lfc" user
$MYSQL_PASSWORD -> the root Mysql password
$LFC_CENTRAL -> list of VOs for which the LFC should be configured as a central catalogue. If you leave this empty, the LFC will be set as a local catalog.
$LFC_LOCAL -> If you want to limit the VOs for your local catalog, add them here.
$LCG_REPOSITORY and CA_REPOSITORY -> you have to set this variables only if you are using a software repository different from the default.
LCG_REPOSITORY=“'rpm LCG/apt/LCG-2_7_0/sl3/en/i386 lcg_sl3 lcg_sl3.updates lcg_sl3.security' 'rpm apt/LCG-2_7_0/sl3/en/i386 lcg_sl3 lcg_sl3.updates lcg_sl3.security‘”
CA_REPOSITORY="rpm apt/LCG_CA/en/i386 lcg"
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

13. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
Support for GILDA VO
VOS="dteam gilda“  add here the VOs you want to support
VO_GILDA_SW_DIR=$VO_SW_DIR/gilda
VO_GILDA_DEFAULT_SE=$CLASSIC_HOST
VO_GILDA_STORAGE_DIR=$CLASSIC_STORAGE_DIR/gilda
VO_GILDA_QUEUES="short long infinite"
VO_GILDA_VOMS_SERVERS="vomss://voms.ct.infn.it:8443/voms/gilda?/gilda"
Add gilda poolaccount in /opt/lcg/yaim/examples/users.conf according the following format:
UID:LOGIN:GID:GROUP:VO:FLAG:
example: …
4451:gildasgm:4400:gilda:gilda:sgm:
4401:gilda001:4400:gilda:gilda::
4402:gilda002:4400:gilda:gilda::
Add the following lines to /opt/lcg/yaim/examples/groups.conf
"/VO=gilda/GROUP=/gilda/ROLE=SoftwareManager":::sgm:
"/VO=gilda/GROUP=/gilda"::::
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

14. Installation and configuration scripts
Start the download and installation of all the needed package using the following command:
/opt/lcg/yaim/scripts/install_node /root/my-site-info.def lcg-LFC_mysql
Start the configuration of the LFC according the information provided into the my-site-info.def with:
/opt/lcg/yaim/scripts/configure_node /root/my-site-info.def LFC_mysql
A new IPTABLES rule is necessary:
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport j ACCEPT
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

15. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
LFC Server Testing
Log into a LCG user interface where the LFC clients commands and lcg-utils are installed:
rpm -qa | grep LFC-client
rpm -qa | grep lcg_util
Set the hostname of the LFC catalog you want to use:
export LFC_HOST=gilda11.fis.uniroma3.it
Be sure to have already initialized a voms proxy:
voms-proxy-info –all
Give a look inside the /grid/gilda folder with:
lfc-ls -l /grid/gilda
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

16. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
Check that LCG_GFAL_INFOSYS variable is correctly set up to your BDII server:
export LCG_GFAL_INFOSYS=<bdii_name>:2170
Use lcg-infosites to discover which SE are available to your VO:
lcg-infosites --vo gilda se
Choose one SE and upload a file with:
lcg-cr -v --vo gilda -d <fadq of the choose SE> -l lfn:/grid/gilda/hostname.jdl file://$PWD/hostname.jdl
Check if the file was correctly registered into the catalog and where it was stored:
lfc-ls -l /grid/gilda/
lcg-lr --vo gilda lfn:/grid/gilda/hostname.jdl
LFC Server Testing (II)
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

17. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006
References
LCG File Catalog (LFC) administrators' guide
LFC Troubleshooting
Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma,

18. Giuseppe La Rocca, INFN Catania  gLite Tutorial  Roma, 18-21.04.2006