US 11,941,255 B2
Storage system and data management method
Hiroaki Akutsu, Tokyo (JP); Mikio Fukuoka, Tokyo (JP); and Eijyu Katsuragi, Tokyo (JP)
Assigned to HITACHI, LTD., Tokyo (JP)
Filed by Hitachi, Ltd., Tokyo (JP)
Filed on Apr. 11, 2022, as Appl. No. 17/717,267.
Application 17/717,267 is a division of application No. 16/734,546, filed on Jan. 6, 2020, granted, now 11,327,661.
Application 16/734,546 is a continuation of application No. 16/228,940, filed on Dec. 21, 2018, granted, now 10,528,274, issued on Jan. 7, 2020.
Application 16/228,940 is a continuation of application No. 14/806,094, filed on Jul. 22, 2015, granted, now 10,168,919, issued on Jan. 1, 2019.
Application 14/806,094 is a continuation of application No. PCT/JP2013/051671, filed on Jan. 25, 2013.
Prior Publication US 2022/0236891 A1, Jul. 28, 2022
Int. Cl. G06F 3/06 (2006.01)
CPC G06F 3/0619 (2013.01) [G06F 3/0617 (2013.01); G06F 3/0631 (2013.01); G06F 3/0665 (2013.01); G06F 3/0685 (2013.01); G06F 3/0689 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A storage system comprising
a plurality of first storage devices, and
a control unit coupled to the plurality of first storage devices, wherein
the control unit is configured to:
form a pool area, which comprises a plurality of virtual parity groups, based on a storage area of the plurality of first storage devices,
manage a mapping which comprises associations between the plurality of virtual parity groups and the plurality of first storage devices,
store, when storing a first data set in a first virtual parity group, the first data set in the plurality of first storage devices associated with the first virtual parity group,
wherein
the first data set comprises a plurality of first data elements whose number is a predetermined number, and
the first data elements are a plurality pieces of data and one or more pieces of redundant data and are respectively stored in different multiple storage devices, and
when a set of second storage devices is added,
form an additional pool area, which comprises an additional virtual parity group, based on the added set of second storage devices,
migrate at least one data element of the first data set of the first virtual parity group to the added set of second storage devices and not migrate at least one other data element of the first data set to the added set of second storage devices, and
change a part of associations for the first data set in order to associate a part of the first virtual parity group with a part of the added set of second storage devices instead of a part of the first storage devices, and maintain another part of the associations of the first virtual parity group with the first storage devices.