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Creating a Blobspace

You can use onspaces, ISA, or ON–Monitor to create a blobspace. Specify a blobspace name of up to 128 bytes. The name must be unique and must begin with a letter or underscore. You can use letters, digits, underscores, and $ characters in the name.

Important:
You can mirror the blobspace when you create it if mirroring is enabled for the database server. Mirroring takes effect immediately.
Before you create a blobspace
  1. Allocate disk space for the blobspace, as described in Allocating Disk Space.
  2. Determine what blobpage size is optimal for your environment.

    For instructions, see Determining Blobpage Size.

To create a blobspace using onspaces
  1. To create a blobspace on UNIX, you must be logged in as user informix or root.

    To create a blobspace on Windows, you must be a member of the Informix-Admin group.

  2. Ensure that the database server is in online, single-user, or quiescent mode, or the cleanup phase of fast-recovery mode.
  3. To add a blobspace, use the onspaces -c -b options.
    1. Specify an explicit pathname for the blobspace. If the blobspace is mirrored, you must specify the pathname and size of both the primary chunk and mirror chunk.
    2. Use the -o option to specify an offset for the blobspace.
    3. Use the -s option to specify the size of the blobspace chunk, in kilobytes.
    4. Use the -g option to specify the blobpage size in terms of the number of disk pages per blobpages.

      See Determining Blobpage Size. For example, if your database server instance has a disk-page size of 2 kilobytes, and you want your blobpages to have a size of 10 kilobytes, enter 5 in this field.

    If you specify an incorrect pathname, offset, or size, the database server does not create the blobspace and displays an error message. Also see What to Do If You Run Out of Disk Space.

  4. After you create the blobspace, you must perform a level-0 backup of the root dbspace and the new blobspace.

The following shows how to create a 10-megabyte mirrored blobspace, blobsp3, with a blobpage size of 10 kilobytes, where the database server page size is 2 kilobytes. An offset of 200 kilobytes for the primary and mirror chunks is specified. The blobspace is created from raw disk space on UNIX. 

onspaces -c -b blobsp3 -g 5 -p /dev/raw_dev1 -o 200 -s 10240 -m /dev/raw_dev2 200

For reference information on creating a blobspace with onspaces, see information on the onspaces utility in the IBM Informix Administrator's Reference.

To create a blobspace with ON-Monitor (UNIX)
  1. Select the Dbspaces > BLOBSpace option.
  2. Enter the name of the new blobspace in the BLOBSpace Name field.
  3. If you want to create a mirror for the initial blobspace chunk, enter Y in the Mirror field.

    Otherwise, enter N.

  4. Specify the blobpage size in terms of the number of disk pages per blobpage in the BLOBPage Size field.

    See Determining Database Server Page Size. For example, if your database server instance has a disk-page size of 2 kilobytes, and you want your blobpages to have a size of 10 kilobytes, enter 5 in this field.

  5. Enter the complete pathname for the initial primary chunk of the blobspace in the Full Pathname field of the primary-chunk section.
  6. Specify an offset in the Offset field.
  7. Enter the size of the chunk, in kilobytes, in the Size field.
  8. If you are mirroring this blobspace, enter the full pathname, size, and optional offset in the mirror-chunk section of the screen.
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