By Fully Pre-allocating a TDEV all the tracks associated with the device are reserved, this may be useful for mission critical apps or avoiding any write miss penalties.

Example SYMCLI:
Single TDEV example:
symconfigure -sid xxx -cmd “start allocate on tdev 0c66 end_cyl=last_cyl allocate_type=persistent;” commit

Range of TDEVs:
symconfigure -sid xxx -cmd “start allocate on tdev 0c6e:1116 end_cyl=last_cyl allocate_type=persistent;” commit

Example UNISPHERE:
From the Unisphere GUI navigate to storage>volumes right click the device you wish to modify and select ‘Start allocate’.