Storage system having non-volatile memory device

Patent metadata

Field	Value
Publication number	US-10915441-B2
Application number	US-201716495752-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Aug 23, 2017
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

An upper system of an NVM device transmits, to the NVM device, a write command that designates a logical address, the write command being associated with an expiration date corresponding to a data expiration date correlated with write target data. The NVM device correlates an expiration date correlated with the write command with a logical address specified from the write command. The NVM device writes pieces of data of which the remaining time which is the time to an expiration date belongs to the same remaining time range to the same physical storage area among the plurality of physical storage areas. The NVM device erases data from a physical storage area when the expiration dates of all pieces of data in the physical storage area have expired.

First claim

The invention claimed is:

1. A storage system comprising:
an NVM device which has NVMs (non-volatile memories) including a plurality of physical storage areas and which provides a logical storage area, performs an internal process including data migration between physical storage areas, and erases data in units of physical storage area; and
an upper system of the NVM device, wherein
the upper system is configured to transmit a write command that designates a logical address to the NVM device, the write command being associated with a stripe expiration date corresponding to a data expiration date correlated with write target data of which stripe data is based on;
the stripe data is part of at least one of the units of physical storage data, stored in a strip and corresponds to the data expiration date;
each of a plurality of stripe expiration dates corresponds to each of the units of physical storage data, and

the NVM device is configured to:
correlate the stripe expiration date with the logical address specified from the write command;
write pieces of data containing a remaining time in the data expiration date to one of the plurality of physical storage areas, the one of the plurality of physical storage areas is selected based on which of the plurality of physical storage areas has a remaining time range that belongs to the same remaining time range that contains the remaining time of the pieces of data to be written; and
erase data from one of the plurality of physical storage areas when the data expiration date of each of the pieces of data in the one of the plurality of physical storage areas have expired and the stripe expiration date of the one of the plurality of physical storage areas has expired.

2. The storage system according to claim 1 , wherein
the storage system includes a plurality of NVM devices which form a RAID (Redundant Array of Independent (or Inexpensive) Disks) group and each of which is the NVM device,
the RAID group is configured to provide a RAID area which is a logical storage area made up of a plurality of stripes,
the logical storage area provided by each of the plurality of NVM devices is made up of a plurality of strips,
each of the plurality of stripes is made up of a plurality of strips provided by each of the plurality of NVM devices,
the upper system is configured to determine, as the stripe expiration date, correlated with the write command transmitted by the upper system, that a latest data expiration date among the data expiration dates of all pieces of strip data that form stripe data based on the write target data is a stripe expiration date which is an expiration date of all of the stripe data, and
the data expiration date of each piece of the strip data is a data expiration date correlated with the write target data corresponding to the strip data.

3. The storage system according to claim 2 , wherein
the write command is correlated with a data expiration date and the stripe expiration date corresponding to the strip data corresponding to the write command,
the NVM device having received the write command is configured to correlate the data expiration date and the stripe expiration date correlated with the write command with a logical address specified from the write command, and
each of the plurality of NVM devices is configured to suppress I/O (Input/Output) of data with respect to a logical address in which a stripe expiration date has not expired even if a data expiration date has expired.

4. The storage system according to claim 3 , wherein
each of the plurality of NVM devices is configured to read strip data of which a write destination is a logical address corresponding to I/O suppression when recovering a parity corresponding to the strip data even if the logical address corresponds to I/O suppression.

5. The storage system according to claim 1 , wherein
the NVM device is configured to manage a plurality of physical storage area groups corresponding to a plurality of stages of remaining time ranges configured such that, the shorter the remaining time, the lower the stage of remaining time range,
one or more physical storage areas belong to each of the plurality of physical storage area groups, and
a lowermost-stage remaining time range which is a remaining time range to which a shortest remaining time belong among the plurality of stages of remaining time ranges is a shortest range.

6. The storage system according to claim 5 , wherein
the lower the stage of remaining time range, the shorter becomes the remaining time range, and
the plurality of stages of remaining time ranges include a remaining time range other than an uppermost-stage remaining time range and a lowermost-stage remaining time range.

7. The storage system according to claim 1 , wherein
the NVM device is configured to write data corresponding to the write command to a physical storage area in which the remaining time specified from the write command belongs to the same remaining time range among the plurality of physical storage areas.

8. An NVM (non-volatile memory) device connected to an upper system, comprising:
NVMs including a plurality of physical storage areas; and
an NVM controller which is a controller which provides a logical storage area, performs an internal process including data migration between physical storage areas, and erases data in units of physical storage area, wherein
the NVM controller is configured to:
receive, from the upper system, a write command that designates a logical address, the write command being associated with a stripe expiration date corresponding to a data expiration date correlated with write target data of which stripe data is based on;
correlate the stripe expiration date with the logical address specified from the write command;
write pieces of data containing a remaining time in the data expiration date to one of the plurality of physical storage areas, the one of the plurality of physical storage areas is selected based on which of the plurality of physical storage areas has a remaining time range that belongs to the same remaining time range that contains the remaining time of the pieces of data to be written; and
erase data from one of the plurality of physical storage areas when the data expiration dates of each of the pieces of data in the plurality of physical storage areas have expired and the stripe expiration date of the one of the plurality of physical storage area has expired,

the stripe data is part of at least one of the units of physical storage data, stored in a strip and corresponds to the data expiration date, and
each of a plurality of stripe expiration dates corresponds to each of the units of physical storage data.

9. A non-transitory computer-readable medium storing a program for causing a non-transitory computer-readable medium to operate as an upper system of an NVM device which has NVMs (non-volatile memories) including a plurality of physical storage areas and which provides a logical storage area, performs an internal process including data migration between physical storage areas, and erases data in units of physical storage area, the program causes the upper system of an NVM device:
specify a data expiration date correlated with write target data;
transmit a write command that designates a logical address to the NVM device, the write command being associated with a stripe expiration date corresponding to the data expiration date correlated with a write target data of which stripe data is based on;
correlate the stripe expiration date correlated with the write command with the logical address specified from the write command;
write pieces of data containing a remaining time in the data expiration date t

Assignees

• Hitachi Ltd
• Hitachi Information & Telecommunication Eng Ltd

Inventors

• Hoshino Koshi
• Homma Shigeo
• Ogawa Junji
• Ohira Yoshinori

Classifications

• G06F3/064

  Management of blocks · CPC title

• G06F12/0868

  Data transfer between cache memory and other subsystems, e.g. storage devices or host systems · CPC title

• G06F2212/7201

  Logical to physical mapping or translation of blocks or pages · CPC title

• G06F12/0246 Primary

  in block erasable memory, e.g. flash memory · CPC title

• G06F2212/1016

  Performance improvement · CPC title