onspaces -c -P: Create a plogspace

Use the onspaces -c -P command to create a plogspace in which to store the physical log.

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Syntax

>>-onspaces -c---- -P--plogspace-------------------------------->

>--+- -p--pathname----------+-- -o--offset-- -s--size----------->
   '- -p--\--\--.--\--drive-'                           

>--+-----------------------------------+--+-----+--------------><
   +- -m--pathname --offset------------+  '- -u-'   
   |                               (1) |            
   '- -m--\--\--.--\--drive offset-----'            

Notes:
  1. Windows Only
Element Purpose Key considerations
-c Creates a plogspace. An instance can have only one plogspace. If a plogspace exists, creating a new one moves the physical log to the new space and drops the old plogspace.
-m pathname offset Specifies an optional path name and offset to the chunk that mirrors the chunk of the new plogspace.

See -p pathname and -o offset in this table.

If you mirror the plogspace, the plogspace chunk cannot be extendable.
-m \\.\drive Specifies the Windows drive for the chunk that mirrors the chunk of the new plogspace.

The drive is the drive letter that is assigned to a disk partition or a constant value and the physical drive number.

Examples:
\\.\F:
\\.\PhysicalDrive2

For drive name syntax, see your operating-system documentation.

-o offset Indicates, in KB, the offset into the disk partition or into the device to reach the chunk of the new plogspace. Unsigned integer. The starting offset must be equal to or greater than 0. The starting offset plus the chunk size cannot exceed the maximum chunk size.

The offset must be a multiple of the page size. The maximum offset is 2 or 4 TB, depending on the platform.

-P plogspace Names the plogspace to be created. The plogspace name must be unique and cannot exceed 128 bytes. It must begin with a letter or underscore and must contain only letters, numbers, underscores, or the $ character.

The syntax must conform to the Identifier segment. For more information, see Identifier.

-p pathname Indicates the disk partition or device of the chunk of the plogspace that you are creating. The chunk must be an existing unbuffered device or buffered file. When you specify a path name, you can use either a full path name or a relative path name. However, if you use a relative path name, it must be relative to the directory that was the current directory when you initialized the database server.

UNIX example (unbuffered device):

/dev/rdsk/c0t3d0s4

UNIX example (buffered device):

/ix/ifmx/db1chunk

Windows example:

c:\Ifmxdata\ol_icecream\mychunk1.dat

-p \\.\drive Specifies the Windows drive to allocate as unbuffered disk space for the plogspace.

The drive is the drive letter that is assigned to a disk partition or a constant value and the physical drive number.

Examples:
\\.\F:
\\.\PhysicalDrive2

For drive name syntax, see your operating-system documentation.

-s size Indicates, in KB, the size of the chunk of the new plogspace. Unsigned integer. The size must be equal to or greater than 1000 KB and a multiple of the page size. The starting offset plus the chunk size cannot exceed the maximum chunk size.

The maximum chunk size is 2 or 4 TB, depending on the platform.

-u Specifies to create an unencrypted space Use this option to create an unencrypted storage space when encryption is enabled by the DISK_ENCRYPTION configuration parameter.

The physical log must be stored on a single chunk. By default the chunk for the plogspace is extendable and the database server expands the plogspace as needed to improve performance.

Examples

The following example creates a plogspace that is called plogdbs that has a size of 40000 KB and an offset of 0:

onspaces -c -P plogdbs -p /dev/chk1 -o 0 -s 40000

The following example creates a mirrored plogspace that is called pdbs1 that has a size of 60000 KB and an offset of 500 KB:

onspaces -c -P pdbs1 -p /dev/pchk1 -o 500 -s 60000 -m /dev/mchk1 0

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