Dbspace chunk files

Chunk files are physical disk spaces used by dbspaces in Informix® Dynamic servers. Each dbspace must consist of at least one chunk file. After you have used a chunk file in a database server, you cannot move it. If you move it, the database server no longer functions. Consequently, the database server might lose data.

Rational® Synergy databases are made up of two parts:

As Rational Synergy databases grow, the capacity to house the metadata must also grow. The Rational Synergy administrator is responsible for managing the growth of the database server. The administrator can monitor the status of a database server by using this command:

Windows: ccmsrv status

UNIX on Informix: ccmsrv status

UNIX on Oracle: ccmsrv status

To expand the capacity of a database server, use this command to perform this operation:

Windows: ccmsrv expand

UNIX on Informix: ccmsrv expand

Attention: Do not perform system backups of chunk files. Backup tools can prevent Informix from being able to access the chunk files, which can result in the database server marking the chunk files as inaccessible. To recover from this condition, you might need to restore from backup or give IBM® Rational Support access to your system.

For information about backing up Rational Synergy databases, see Performing database integrity checks. It is more efficient to archive the database server, as described in Database server archiving and restoration overview, rather than backing up chunk files.

If you must back up chunk files as part of a system backup, you must take the database server offline to avoid serious data corruption.

A Rational Synergy database server has four dbspaces:

The rootdbs and log dbspaces contain system data. These dbspaces are not used to store Rational Synergy database metadata. The ccm dbspace stores the Rational Synergy database metadata.

You can specify the size of the ccm dbspace during main or additional server creation when you install Rational Synergy. The value is based on the number of users that you configure for the database server. This initial value is only a rough estimate, and does not suit the needs for all development teams. The Rational Synergy administrator monitors the usage of this dbspace and expands it if necessary.

When expanding the ccm dbspace:


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