VMAX Device types

TDAT:
TDAT, or thin data device, is an internal LUN which is assigned to a thin pool. Each TDAT LUN is comprised of multiple physical drives configured to provide a specific data protection type. An example of a TDAT device might be a Raid-5(3+P)LUN.
Another common example would be a Raid–1 mirrored LUN. Multiple TDAT devices are assigned to a pool.  When creating a thin pool LUNs for presentation to a host the data is striped across all of the TDAT devices in the pool. The pool can be enlarged by adding devices and rebalancing data placement (background operations with no impact to the host).

Thin Devices (TDEVs):
They consume no disk space. These are only pointers residing in memory. Allocation is done in 768 KB increment (12 tracks) when they are "bound". It  is a host accessible(redundantlypresented to an FA port) back-end LUN device that is “bound” to a thin device pool (TDATs) for its capacity needs.
As stated above, a TDEV is a host presentable device that is striped across the back end TDAT devices. The stripe size is 768K.
Each TDEV is presented to an FA port for host server allocation When utilizing thin provisioning, Thin Pool LUNs are employed. The utilization of TDEVs is required to use EMC ®Fully Automated Storage Tiering Virtual Provisioning (FAST/VP features.


Meta Devices (aka Meta Volumes:
They allow to increase the size of device presented to a host. Symmetrix Device size maximum is 240 GB,


Data devices:
Non adressable Symmetrix private device. (Cannot be mapped to a front end port)
Provide space to thin devices.
You "add" data devices to thin pool, but you "bind" thin devices to a thin pool.