Creating a blobspace

You can use onspaces to create a blobspace.

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.

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.

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, 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.
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.


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