Patent ID: 8819338

Claim:
A storage system comprising: a plurality of flash packages, each of which includes a plurality of flash chips to store data or parity, and a device controller configured to be coupled to the plurality of flash chips, and a RAID controller configured to be coupled to the plurality of flash packages and to control the plurality of flash packages as a RAID group, the plurality of flash packages including a first flash package storing old data and a second flash package storing old parity; wherein the storage system is configured to perform steps of: generating first intermediate parity based on the old data stored in the first flash package and new data sent from a host computer by a first device controller of the first flash package; transferring the first intermediate parity from the first flash package to a second flash package which is one of the plurality of flash packages and has stored old parity; generating first new parity based on the first intermediate parity and the old parity stored in the second flash package by a second controller of the second flash package; and invalidating the old data by the first device controller after storing the first new parity on a flash chip of the second flash package.