Creating a blobspace

You can use onspaces or ON-Monitor to create a blobspace.

Before you begin

Before you create a blobspace:
  1. Allocate disk space for the blobspace, as described in Allocate disk space.
  2. Determine what blobpage size is optimal for your environment.

    For instructions, see Determine blobpage size.

About this task

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.

To create a blobspace using onspaces:

Procedure

  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, administration, 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 path name for the blobspace. If the blobspace is mirrored, you must specify the path name 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 KB.
    4. Use the -g option to specify the blobpage size in terms of the number of disk pages per blobpages.

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

      If you specify an incorrect path name, 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.

Example

The following example shows how to create a 10-megabyte mirrored blobspace, blobsp3, with a blobpage size of 10 KB, where the database server page size is 2 KB. An offset of 200 KB 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 about creating a blobspace with onspaces, see information about the onspaces utility in the HCL® Informix® Administrator's Reference.

What to do next

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

  5. Enter the complete path name 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 KB, in the Size field.
  8. If you are mirroring this blobspace, enter the full path name, size, and optional offset in the mirror-chunk section of the screen.