Partitions and offsets

The system administrator might divide a physical disk into partitions, which are different parts of a disk that have separate path names. Although you must use an entire disk partition when you allocate a chunk on a raw disk device, you can subdivide partitions or cooked files into smaller chunks using offsets.

Tip: With a 4-terabyte limit to the size of a chunk, you can avoid partitioning a disk by assigning a single chunk per disk drive.

You can use an offset to indicate the location of a chunk on the disk partition, file, or device. For example, suppose that you create a 1000 KB chunk that you want to divide into two chunks of 500 KB each. You can use an offset of 0 KB to mark the beginning of the first chunk and an offset of 500 KB to mark the beginning of the second chunk.

You can specify an offset whenever you create, add, or drop a chunk from a dbspace, blobspace, or sbspace.

You might also be required to specify an offset to prevent the database server from overwriting partition information.