Auto-carving is useful for creating multiple volumes out of large arrays at the hardware level. Then, when you boot to the operating system, each volume appears as a different disk drive, simplifying the partitioning required at the operating system level.
When the Auto-Carving policy is on, any new unit larger than a specified size (known as the
carve size) will be created as multiple volumes that can be addressed by the operating system as separate volumes. These chunks are sometimes known as multiple LUNs (logical units). However, throughout the 3ware documentation, they are referred to as
volumes.
For example, using the default carve size of 2 TB, if the unit is 2.5 TB then it will contain two volumes, with the first volume containing 2 TB and the second volume containing 0.5 TB. If the unit is 5.0 TB then it will contain 3 volumes, with the first two volumes containing 2 TB each and the last volume containing 1 TB. (
Note: If a specific Boot Volume was also specified in 3BM or CLI, the first volume will be the size specified for the Boot Volume, and then the carve size will be applied to the remainder of the unit. For more information, see
Boot volume size.)
Each volume can be treated as an individual disk with its own file system. The default carve size is 2 TB; you can change this to a setting in the range of 1 TB to 32 TB (1024 GB to 32768 GB). 3ware firmware supports a maximum of 32 volumes per controller, up to a total of 32 TB.
You must turn on the Auto-Carving policy before creating the unit. Units created with this policy turned off will not be affected by a change to the policy. If the policy is turned off later, units that have been carved into volumes will retain their individual volumes; existing data is not affected.
