Creating an Informix database server for UNIX

You can create a database server on the installation machine or on a remote host. Installers often create a database server on the installation machine. However, you are not required to do so. You can make any host a database server if the machine meets the system requirements and a valid installation directory for that platform is visible (for example, local or NFS-mounted).

Before you begin

Before creating the database server, see Preparing an Informix database server.

About this task

For example, the installation directory for Solaris is /usr/local/ccm72 on the solaris1 machine and you want to create a database server on solaris2, You can NFS-mount the installation directory on solaris2. Then, create a database server on solaris2. Creating the database server automatically adds an entry for solaris2 to the sqlhosts file in the Solaris installation directory.

You can allow a database server to run server processes for a different type of platform. For example, to make an AIX® database server, aix1, available as a database server for Solaris 9 or 10 machines, add the aix1 entry manually to the Solaris 9 or 10 installation directory sqlhosts file.

Note: When creating the database server on a different machine than the installation machine, ensure that the database server is configured correctly. See Modifying database server parameter values.

Procedure

To create the database server for UNIX:

  1. Log on to the database server as user root.

    If your database server is the same as your installation machine, you are logged in already as root.

  2. Create a directory for the Informix® dbspace (chunkfiles).

    Replace informix_chunkfiles with the path to your Informix chunk files. When you create chunk files:

    • Place the chunk files where no one can remove them.
    • Create the chunk file directory (for example, /data/informix_chunkfiles) on the machine where the database server will run.
    • For the best performance and reliability, use raw partitions for Informix chunk files. (In the rare event of file system corruption, cooked files are affected but raw files are not.)
    • Ensure that the names of your chunk files paths contain fewer than 66 characters.
    • The maximum chunk files size is 4 TB (Terabyte). If you need more than 4 TB, contact IBM® Rational® Software Support.
    Attention: Do not back up Informix data files as normal UNIX files. Avoid putting this directory under the installation directory, $CCM_HOME, or under the ccm_root or informix home directory.

    See Informix chunk files for more information about creating chunk files.

    root# mkdir informix_chunkfiles
    root# chown informix informix_chunkfiles
    root# chgrp informix informix_chunkfiles
    root# chmod 770 informix_chunkfiles
  3. Create a directory for the Rational Synergy databases.

    Replace ccmdb with the database directory. For example, /data/ccmdb.

    Attention: Avoid putting the database directory under the installation directory. If necessary, you can create the directory under the ccm_root home directory, if the ccm_root home directory is not under the installation directory.
    root# mkdir ccmdb
    root# chown ccm_root ccmdb
    root# chgrp ccm_root ccmdb
    root# chmod 755 ccmdb
  4. Create the database server.

    You can create the database server interactively or by using a configuration file.

    Use the directory created in step 2 (informix_chunkfiles) for the primary chunk path for the root dbspace. Then, use the defaults for everything else except the number of users. Set to the expected number of simultaneous users of all databases on this server. Round up to the nearest 10.

    Chunk files path names must be fewer than 66 characters. Also, the default space suggested for the root, temp, and log dbspaces is about 1 MB per user. For the ccm dbspace it is about 2 MB per user. Therefore, for the default 40 users, the total is about 220 MB.

    Type valid values for the number of CPUs, number of users, and server number.

    Note: If you have other Informix installations, either active or inactive, the default server number that ccmsrv create attempts to use might already be in use. An error like this displays in the log file:
    11:13:05  shmget: [EEXIST][17]: key 52574801: shared
    memory already exists
    11:13:05  mt_shm_init: can't create resident segment

    Correct this problem by using a different server number.

    Also, if you need to increase the size of your shared memory kernel parameters, you might see an error like this one in the log file.

    16:53:12  shmat: [EMFILE][24]: out of shared memory
    segments, check system SHMSEG
    16:53:12  mt_shm_init: can't create resident segment

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