A method of implementing online restriping of a volume, the volume being arranged into a plurality of columns across which data is arranged in a plurality of stripes according to a first Virtual to Physical, V2P, mapping in a storage area network, the storage area network including a fibre channel fabric, the fibre channel fabric including at least one switch having a plurality of ports (1201, 1203), including first, second and third ports each having an associated data path processor implementing logic for each respective port, the method comprising: instantiating, at the first port, a first instance of the volume comprising the first V2P mapping for enabling I/O operations to be performed at a first virtual enclosure comprising a YET-TO-BE-DONE portion of the volume; instantiating, at the second port, a second instance of the volume comprising a second V2P mapping for enabling I/O operations to be performed at a second virtual enclosure comprising an ALREADY-DONE portion of the volume; and performing restriping operations at the volume; and enabling the first port and the second port to perform I/O operations at the volume concurrently while at least a portion of the restriping operations are being performed at the volume, wherein enabling comprises: defining a third virtual enclosure comprising an ACTIVE region of the volume for executing a first portion of restriping operations at the third port; allowing the first port to perform I/O operations at the first YET-TO-BE-DONE portion of the volume according to the first V2P mapping; allowing the second port to perform I/O operations at the second ALREADY-DONE portion of the volume according to the second V2P mapping; and locking of the ACTIVE region during execution of the first portion of restriping operations, wherein the locking of the ACTIVE region includes denying read/write access to the ACTIVE region by the first port and the second port. instantiating, at the first port, a first instance of the volume comprising the first V2P mapping for enabling I/O operations to be performed at a first virtual enclosure comprising a YET-TO-BE-DONE portion of the volume; instantiating, at the second port, a second instance of the volume comprising a second V2P mapping for enabling I/O operations to be performed at a second virtual enclosure comprising an ALREADY-DONE portion of the volume; and performing restriping operations at the volume; and enabling the first port and the second port to perform I/O operations at the volume concurrently while at least a portion of the restriping operations are being performed at the volume, wherein enabling comprises: defining a third virtual enclosure comprising an ACTIVE region of the volume for executing a first portion of restriping operations at the third port; allowing the first port to perform I/O operations at the first YET-TO-BE-DONE portion of the volume according to the first V2P mapping; allowing the second port to perform I/O operations at the second ALREADY-DONE portion of the volume according to the second V2P mapping; and locking of the ACTIVE region during execution of the first portion of restriping operations, wherein the locking of the ACTIVE region includes denying read/write access to the ACTIVE region by the first port and the second port. defining a third virtual enclosure comprising an ACTIVE region of the volume for executing a first portion of restriping operations at the third port; allowing the first port to perform I/O operations at the first YET-TO-BE-DONE portion of the volume according to the first V2P mapping; allowing the second port to perform I/O operations at the second ALREADY-DONE portion of the volume according to the second V2P mapping; and locking of the ACTIVE region during execution of the first portion of restriping operations, wherein the locking of the ACTIVE region includes denying read/write access to the ACTIVE region by the first port and the second port.