In this section we will have a look at the configuration and log files of dCache.

The dCache software is installed in one directory, normally /opt/d-cache/. All configuration files can be found here. In the following relative filenames will always be relative to this directory.

In the previous section we have already seen how a domain is restarted:

[root] # /opt/d-cache/bin/dcache restart <domainName>

Log files of domains are by default stored in /var/log/<domainName>.log. We strongly encourage to configure logrotate to rotate the dCache log files to avoid filling up the log file system. This can typically be achieved by creating the file /etc/logrotate.d/dcache with the following content:

/var/log/*Domain.log {
    compress
    rotate 100
    missingok
    copytruncate
}

The files config/<domainName>Setup contain configuration parameters for the domain. These files are typically symbolic links to config/dCacheSetup. This is the primary configuration file of dCache.

The only files which are different for each domain are config/<domainName>.batch. They describe which cells are started in the domains. Normally, changes in these files should not be necessary. However, if you need to change something, consider the following:

Since the standard config/<domainName>.batch files will be overwritten when updating to a newer version of dCache (e.g. with RPM), it is a good idea to modify only private copies of them. When choosing a name like config/<newDomainName>.batch you give the domain the name <newDomainName>. The necessary links can be created with

[root] # cd /opt/d-cache/config/
[root] # ../jobs/initPackage.sh

Then the old domain can be stopped and the new one started:

[root] # /opt/d-cache/bin/dache stop <domainName>
[root] # /opt/d-cache/bin/dcache start <newDomainName>

More details about domains and cells can be found in Chapter 5, The Cell Package.

The most central component of a dCache instance is the PoolManager cell. It reads additional configuration information from the file config/PoolManager.conf at start-up. However, in contrast to the config/<domainName>Setup files, it is not necessary to restart the domain when changing the file. We will see an example of this below.

Similar to config/PoolManager.conf, pools read their configuration from <poolDir>/pool/setup at startup.