onspaces -c -P: Create a plogspace
Use the onspaces -c -P command to create a plogspace in which to store the physical log.
- 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: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: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 40000The 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