# US 2019/0243733 A1 · System and method for efficient comparison of mirrored storage devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0243733 A1 - Document ID: US20190243733A1 - Status: Published application - Kind: A1 - Application number: 16/270,017 - Filed: 2019-02-07 - Published: 2019-08-08 - Earliest claimed: 2018-02-07 - Assignees: Excelero Storage Ltd. - Applicants: Excelero Storage Ltd. - Inventors: Yaniv ROMEM; Omri MANN; Ofer OSHRI; Kirill SHOIKHET; Daniel HERMAN SHMULYAN - Web page: https://patentgrep.com/patent/US20190243733A1 ## CPC - G06F 11/1448: {Management of the data involved in backup or backup restore} - G06F 11/2064: {while ensuring consistency} - G06F 11/2069: {Management of state, configuration or failover} - G06F 11/2082: {Data synchronisation} - G06F 11/2056: {by mirroring} - G06F 2201/805: Real-time - G06F 2201/82: Solving problems relating to consistency - G06F 2201/835: Timestamp - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A system and method for comparing mirrored storage devices. The method includes: selecting, from a storage slice of a first storage device and at least a second storage device, corresponding storage blocks that are not trimmed blocks, wherein trimmed blocks are blocks within a storage device marked for erasure; comparing the corresponding storage blocks such that a non-trimmed block of the first storage device is compared to a corresponding non-trimmed block of the second storage device to determine which storage blocks do not match; and performing a recovery operation between the non-trimmed block of the first storage device and a non-matching corresponding first non-trimmed block of the second storage device. ## Claims ### Claim 1 A method for comparing mirrored storage devices, comprising: selecting, from a storage slice of a first storage device and at least a second storage device, corresponding storage blocks that are not trimmed blocks, wherein trimmed blocks are blocks within a storage device marked for erasure; comparing the corresponding storage blocks such that a non-trimmed block of the first storage device is compared to a corresponding non-trimmed block of the second storage device to determine which storage blocks do not match; and performing a recovery operation between the non-trimmed block of the first storage device and a non-matching corresponding first non-trimmed block of the second storage device. ### Claim 2 (depends on 1) The method of claim 1, further comprising: marking all blocks of the slice as trimmed blocks when it is determined that the slice contains any blocks that are trimmed. ### Claim 3 (depends on 1) The method of claim 1, further comprising: trimming a block in the at least a second storage device when a corresponding block of a first storage device is determined to be trimmed. ### Claim 4 (depends on 1) The method of claim 1, wherein the determination if a block is trimmed is based on metadata describing the contents of the block. ### Claim 5 (depends on 1) The method of claim 1, wherein comparing the non-trimmed blocks of the first storage to the non-trimmed blocks of the second storage comprises comparing metadata of the first block and metadata of the second block. ### Claim 6 (depends on 5) The method of claim 5, wherein the metadata is a hash value of the contents of the non-trimmed block. ### Claim 7 (depends on 5) The method of claim 5, wherein the metadata a timestamp value indicating when the contents of the non-trimmed block were written, and wherein it is determined that the more recent of the blocks is a mirrored block. ### Claim 8 (depends on 1) The method of claim 1, the recovery operation is performed in response to detecting one or more of the storage devices are recovering from a failure. ### Claim 9 (depends on 1) The method of claim 1, wherein the number of blocks determined to be trimmed blocks is configurable. ### Claim 10 A non-transitory computer readable medium having stored thereon instructions for causing a processing circuitry to perform a process, the process comprising: selecting, from a storage slice of a first storage device and at least a second storage device, corresponding storage blocks that are not trimmed blocks, wherein trimmed blocks are blocks within a storage device marked for erasure; comparing the corresponding storage blocks such that a non-trimmed block of the first storage device is compared to a corresponding non-trimmed block of the second storage device to determine which storage blocks do not match; and performing a recovery operation between the non-trimmed block of the first storage device and a non-matching corresponding first non-trimmed block of the second storage device. ### Claim 11 A system for comparing mirrored storage devices, comprising: a processing circuitry; and a memory, the memory containing instructions that, when executed by the processing circuitry, configure the system to: select, from a storage slice of a first storage device and at least a second storage device, corresponding storage blocks that are not trimmed blocks, wherein trimmed blocks are blocks within a storage device marked for erasure; compare the corresponding storage blocks such that a non-trimmed block of the first storage device is compared to a corresponding non-trimmed block of the second storage device to determine which storage blocks do not match; and perform a recovery operation between the non-trimmed block of the first storage device and a non-matching corresponding first non-trimmed block of the second storage device. ### Claim 12 (depends on 11) The system of claim 11, wherein the system is further configured to: mark all blocks of the slice as trimmed blocks when it is determined that the slice contains any blocks that are trimmed. ### Claim 13 (depends on 11) The system of claim 11, wherein the system is further configured to: trim a block in the at least a second storage device when a corresponding block of a first storage device is determined to be trimmed. ### Claim 14 (depends on 11) The system of claim 11, wherein the determination if a block is trimmed is based on metadata describing the contents of the block. ### Claim 15 (depends on 11) The system of claim 11, wherein comparing the non-trimmed blocks of the first storage to the non-trimmed blocks of the second storage comprises comparing metadata of the first block and metadata of the second block. ### Claim 16 (depends on 15) The system of claim 15, wherein the metadata a hash value of the contents of the non-trimmed block. ### Claim 17 (depends on 15) The system of claim 15, wherein the metadata a timestamp value indicating when the contents of the non-trimmed block were written, and wherein it is determined that the more recent of the blocks is a mirrored block. ### Claim 18 (depends on 11) The system of claim 11, the recovery operation is performed in response to detecting one or more of the storage devices are recovering from a failure. ### Claim 19 (depends on 11) The system of claim 11, wherein the number of blocks determined to be trimmed blocks is configurable.