The version 0 DCO volume layout supports only traditional (third-mirror) volume snapshots that are administered using the vxassist command. Full-sized and space-optimized instant snapshots are not supported with this DCO layout.

The size of each map can be changed by specifying the dcolen attribute to the vxassist command when the volume is created. The default value of dcolen is 132 blocks (the plex contains 33 maps, each of length 4 blocks). To use a larger map size, multiply the desired map size by 33 to calculate the value of dcolen. For example, to use an 8-block map, specify dcolen=264. The maximum possible map size is 64 blocks, which corresponds to a dcolen value of 2112 blocks.

The size of a DCO plex is rounded up to the nearest integer multiple of the disk group alignment value. The alignment value is 8KB for disk groups that support the Cross-platform Data Sharing (CDS) feature. Otherwise, the alignment value is 1 block.