# US 8,572,401 B1 · Systems and methods for securing data of volume mirrors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,572,401 B1 - Document ID: US8572401B1 - Status: Granted - Kind: B1 - Application number: 12/533,783 - Filed: 2009-07-31 - Granted: 2013-10-29 - Earliest claimed: 2009-07-31 - Assignees: Symantec Corporation - Applicants: Roshni Jaywantsingh Patil - Inventors: Roshni Jaywantsingh Patil - Web page: https://patentgrep.com/patent/US8572401B1 ## CPC - G06F 21/6218: {to a system of files or objects, e.g. local or distributed file system or database} - G06F 11/2094: {Redundant storage or storage space (G06F11/2056 takes precedence)} - G06F 11/2097: {maintaining the standby controller/processing unit updated (initialisation or re-synchronisation thereof G06F11/1658 and subgroups)} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Various computer-implemented methods for securing data of replicated volumes are disclosed. In one example, an exemplary method for performing such a task may include: 1) identifying a set of plexes of a replicated volume, 2) identifying, within the set of plexes, at least one non-trusted plex, 3) intercepting data to be replicated to the non-trusted plex, 4) encrypting the data to be replicated to the non-trusted plex, and then 5) writing the encrypted data to the non-trusted plex. Various other methods, systems, and computer-readable media are also disclosed. ## Claims ### Claim 1 A computer-implemented method for securing data of volume mirrors, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: identifying a set of plexes of a replicated volume; identifying, within the set of plexes, at least one non-trusted plex; intercepting data to be replicated to the non-trusted plex, the data to be replicated to the non-trusted plex originating from an attempt by an application to write the data to the replicated volume; simulating, before encrypting the data to be replicated to the non-trusted plex, successful synchronous replication of the data to the non-trusted plex so that the application is not slowed by encrypting the data to be replicated to the non-trusted plex during the attempt by the application to write the data to the replicated volume; encrypting the data to be replicated to the non-trusted plex; asynchronously replicating the encrypted data to the non-trusted plex; wherein the computer-implemented method avoids the performance of unnecessary decryption operations by: refraining from encrypting data to be replicated to trusted plexes; preferring to fulfill read requests for the replicated volume through trusted plexes instead of non-trusted plexes. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, further comprising: receiving a request to read the data from the replicated volume; retrieving the data from the non-trusted plex; decrypting the data retrieved from the non-trusted plex. ### Claim 3 (depends on 1) The computer-implemented method of claim 1, further comprising determining whether the application requires a short response time on write attempts; wherein simulating successful synchronous replication of the data to the non-trusted plex is performed in response to determining that the application requires a short response time on write attempts. ### Claim 4 (depends on 1) The computer-implemented method of claim 1, further comprising: before asynchronously replicating the encrypted data to the non-trusted plex: creating a dirty region log for the non-trusted plex; setting a dirty flag in the dirty region log for the data to be replicated; receiving confirmation from the non-trusted plex of successful replication of the encrypted data to the non-trusted plex; clearing the dirty flag in response to receiving the confirmation from the non-trusted plex of successful replication of the encrypted data to the non-trusted plex. ### Claim 5 (depends on 1) The computer-implemented method of claim 1, wherein intercepting the data to be replicated to the non-trusted plex comprises: detecting that the non-trusted plex has become detached from the replicated volume; tracking data changes to the replicated volume with a dirty region log. ### Claim 6 (depends on 5) The computer-implemented method of claim 5, wherein encrypting the data to be replicated to the non-trusted plex comprises encrypting data tracked as changed in the dirty region log. ### Claim 7 (depends on 1) The computer-implemented method of claim 1, further comprising assigning an encryption key for each non-trusted plex in the set of plexes. ### Claim 8 (depends on 1) The computer-implemented method of claim 1, wherein asynchronously replicating the encrypted data to the non-trusted plex comprises writing the encrypted data to an encrypted storage replication log on a bunker site. ### Claim 9 (depends on 8) The computer-implemented method of claim 8, further comprising: determining that a primary site containing the replicated volume has failed; identifying a remote site comprising an asynchronous replication of the replicated volume, the remote site further comprising a decryption key for the encrypted data; transferring synchronously-replicated data from the encrypted storage replication log to the remote site. ### Claim 10 (depends on 1) The computer-implemented method of claim 1, wherein intercepting data to be replicated to the non-trusted plex comprises detecting a snapshot of the replicated volume to be stored in the non-trusted plex. ### Claim 11 (depends on 10) The computer-implemented method of claim 10, further comprising: tracking changes made to the replicated volume with a data change object; identifying a request to restore the snapshot of the replicated volume from the non-trusted plex; using the data change object to identify changed data since the snapshot was created; decrypting the changed data from the non-trusted plex; writing the decrypted changed data to the replicated volume. ### Claim 12 (depends on 11) The computer-implemented method of claim 11, further comprising: before writing the decrypted changed data to the replicated volume, receiving a request to read data changed since the snapshot was created; reading the data changed since the snapshot was created from the non-trusted plex. ### Claim 13 (depends on 1) The computer-implemented method of claim 1, wherein: intercepting the data to be replicated to the non-trusted plex comprises intercepting application data; encrypting the data to be replicated to the non-trusted plex comprises encrypting the application data. ### Claim 14 (depends on 13) The computer-implemented method of claim 13, further comprising writing, to the non-trusted plex, unencrypted metadata relating to the data to be replicated. ### Claim 15 (depends on 1) The computer-implemented method of claim 1, further comprising making a decryption key for the non-trusted plex available to a trusted application. ### Claim 16 (depends on 1) The computer-implemented method of claim 1, wherein encrypting the data to be replicated to the non-trusted plex comprises encrypting the data using the same level of granularity as used when synchronizing the data. ### Claim 17 (depends on 1) The computer-implemented method of claim 1, wherein asynchronously replicating the encrypted data to the non-trusted plex comprises writing the data to the non-trusted plex on at least one of: a remote site in a campus center; a non-trusted storage site; a cloud environment. ### Claim 18 A system for securing data of replicated volumes, the system comprising: an identification module programmed to: identify a set of plexes of a replicated volume; identify, within the set of plexes, at least one non-trusted plex; an interception module programmed to intercept data to be replicated to the non-trusted plex, the data to be replicated to the non-trusted plex originating from an attempt by an application to write the data to the replicated volume; an encryption module programmed to encrypt the data to be replicated to the non-trusted plex; a writing module programmed to: simulate, before encrypting the data to be replicated to the non-trusted plex, successful synchronous replication of the data to the non-trusted plex so that the application is not slowed by encrypting the data to be replicated to the non-trusted plex during the attempt by the application to write the data to the replicated volume; asynchronously replicate the encrypted data to the non-trusted plex; wherein the system avoids the performance of unnecessary decryption operations due to: the encryption module being programmed to refrain from encrypting data to be replicated to trusted plexes; a request module programmed to prefer fulfilling read requests for the replicated volume through trusted plexes instead of non-trusted plexes; at least one processor configured to execute the identification module, the interception module, the encryption module, the writing module, and the request module. ### Claim 19 A non-transitory computer-readable-storage medium comprising one or more computer-executable instructions that, when executed by at least one processor of a computing device, cause the computing device to: identify a set of plexes of a replicated volume; identify, within the set of plexes, at least one non-trusted plex; intercept data to be replicated to the non-trusted plex, the data to be replicated to the non-trusted plex originating from an attempt by an application to write the data to the replicated volume; simulate, before encrypting the data to be replicated to the non-trusted plex, successful synchronous replication of the data to the non-trusted plex so that the application is not slowed by encrypting the data to be replicated to the non-trusted plex during the attempt by the application to write the data to the replicated volume; encrypt the data to be replicated to the non-trusted plex; asynchronously replicate the encrypted data to the non-trusted plex; wherein the computer-executable instructions cause the computing device to avoid the performance of unnecessary decryption operations by: refraining from encrypting data to be replicated to trusted plexes; preferring to fulfill read requests for the replicated volume through trusted plexes instead of non-trusted plexes.