Linux Hall C Analyzer installation kit

Logo use licensed from Linux Journal

Red Hat 4.2 and 5.0 users please see the new RedHat Linux Hall C Analyzer installation kit

The Hall C analyzer can be run on most reasonably current x86 Linux systems. While not exaustive, some of the requirements include:

Linux running an ELF compatible kernel. Version 2.0 or later is recommended.
ELF libraries. /lib should contain libc.so.5.x.x. libc.so.5.3.12 or later is recommended.
GCC. Version 2.7.2 or later is recommended.
Lots of memory. 32 MB or more is recommended, 16 will probably work.
Lots of disk space.

Getting started

These instructions assume that the reader is already familier with running the Hall C analyzer on HPUX or other systems.

To get started, download "Linux Hall C Analyzer installation kit", grover.tgz. Pick a directory to to untar it into. Lets call this directory GROVER. (In my case, GROVER was ~saw/grover). It is untarred with

	cd GROVER
	tar -zxf grover.tgz

System configuration

Before installation of the analyzer can begin, several system level actions are required.

Arrange to readonly NFS mount a disk containing the Csoft directory. If at TJNAF, this directory may be mounted from wood:/home/saw/Csoft.
Install CERNLIB. At TJNAF, cernlib may be NFS Mounted from wood:/usr/local/cernlib. (This directory also contains CERNLIB compiled for the Absoft fortran compiler in /usr/local/cernlib/96a_absoft.)
Get a new version of f2c from the installation kit. (This version came from ftp://ftp.cc.gatech.edu/pub/linux/devel/lang/fortran/f2c-960717.elf.tgz)
The new f2c package is installed by running the following from the directory "/",
```
	cd /
	tar -zxf GROVER/f2c-960717.elf.tgz
```

Copy f77 and url_get from the installation kit to /usr/bin and /usr/local/bin with

	cp GROVER/f77 /usr/bin
	chmod 755 /usr/bin/f77
	cp GROVER/url_get /usr/local/bin
	chmod 755 /usr/local/bin/url_get

It is strongly recommended that the Network Time Protocol Daemon (xntpd) be run to keep the Linux machines clock synchronized with the machine from which the Csoft software is mounted.

Setting up the analyzer source tree

The following instructions set up the master source tree (Csoft directory) against which individual users may build personal analyzers.

Edit the file GROVER/Groverup. Find the line that starts with "Csoft_READONLY". Set the definition of the variable to the path of the directory Csoft that has been NFS mounted above. If necessary, edit the definition of CERN_ROOT on the next line.
Pick an account from which to administer the analyzer software for the Linux machine. From the root directory of that account source the Csoftup script:
```
	cd ~
	source GROVER/Groverup
```
This will accomplish several things. It will add environment variables to ~/.bash_profile and also define these variables for the current logon. These variables are
```
	NFSDIRECTORY	The location of the NFS mounted readonly copy
			of the analyzer source code.
	CERN_ROOT	Directory containing CERN bin and lib directories.
	Csoft		The local copy of the master source and library tree
```
Groverup also creates the Csoft directory tree with all of the appropriate makefiles and source code.
Do the commands
```
	cd $Csoft/SRC
	make
```

Setting up a "replay" directory in a user account

Each user that will do analysis on the Linux machine must set up a replay directory similar to what is set up on HP workstations. The following procedure may be used.

Create a replay directory under your HPUX account using the Oscar procedure.
Make a tar file of the replay directory made by oscar. For example, if the replay directory is ~/replay, type
```
	tar -zcf myreplay.tgz ~/replay
```
Transfer this tar file to your Linux account.
From your home directory untar the tar file with, for example,
```
	tar -zxf myreplay.tgz
```
Edit or create ~/.bash_profile. Copy from the .bash_profile made by Groverup the definitions for CERN_ROOT and Csoft. Also add to this file the proper definition for ENGINE_CONFIG_FILE. Most likely this will be
```
	export ENGINE_CONFIG_FILE=~/replay/REPLAY.PARM
```
Go to the SRC directory under replay.
Copy the file Makefile in the GROVER directory to this source directory. This step will not be necessary once the Linux changes are integrated into the master copy of this makefile.
Type make. This should compile a personal analyzer.
Copy some data runs to local disk, edit REPLAY.PARM appropriately and replay.

Getting data files

The cache disks, which hold data runs that have been retrieved from the silo can be read-only mounted by any machine at TJNAF. Here is a script that will mount the cache disks on a linux machine.

If a data run is to be analyzed several times, it is helpful to copy it to a local drive.

Data that has been recently acquired and that is not in the computer center silo is not available with NFS. However, a special web server is running on the cdaq machines that is designed to only deliver data files and only to machines on site. The command url_get, included in the above installation kit can be used to retrieve these runs. To do this, use the following for the file name in REPLAY.PARM:

	g_data_source_filename = '|url_get http://cdaq1:2000/%d'

url_get, it it's first contact with the special web server on chdr1 will determine which machine the data file is on and redirect it's connection to that machine so that the data file will be delivered in the most efficient way possible.

url_get may also be used as a standalone program to copy a run to a local disk. For example, nov96_12976.log may be copied to the current directory with

	url_get http://chdr1:2000/12976 > nov96_12976.log

Other ways of getting data files

In addition to url_get, any command that sends a data file to standard output may be used in the Hall C analyzer. For example, rsh might be used if url_get is not working or the data file is not in a location that the special web server searches. For example, the following filename specification will work for recently acuired data on cdaq1.

g_data_source_filename = 'rsh cdaq1 -l yourusername "cat /cdaq1/usr/user1/cdaq/coda/runlist/nov96_%d.log"'

For the remote shell command to work, you must list the node name of your linux machine in the .rhosts file in your home directory on cdaq1. This is generally considered not to be a good idea from a security point of view.

Using compressed files

Saving compressed files on your local disk can increase the amound of data that you can hold locally. File name secifications like

	g_data_source_filename = '|gunzip < nov96_%d.log.gz'

will decompress the data file on the fly. The event reading routines will actually automatically detect compressed files and decompress them, so the specification

	g_data_source_filename = 'nov96_%d.log.gz'

is sufficient.

Note to users of non Hall C applications:. If you are trying to apply these techniques of retrieving data to CODA replay applications other than the Hall C analyzer, you may need to get the improved version of evio.c.

Last update 19 December 1996

saw@jlab.org