Abstract: Described herein is a method, system, and non-transitory computer readable medium for preventing data loss from both producer and consumer systems in continuous availability event-driven applications. The process for preventing data loss may replicate events at the broker level, and selectively receive replica events at the consumer level to account for the case the originally sent event is not received, while conserving computer and network resources. Alternatively, events and replica events may be received in duplicate. In either mode of reception, machine-learning may be used for implementing algorithms which further help to conserve resources and aid in preventing further data loss.

Abstract: Replication of tags in global scale systems is described. A source node creates a file and a grouping tag for the file. The source node stores the grouping tag in a location in metadata for the file. When preparing for replication, the source node retrieves the grouping tag from the location in the metadata. If the legacy location in the metadata includes any value which was stored after the most recent replication involving the file, and the size of the legacy location in the metadata was not changed after the most recent replication involving the file, the system adds the grouping tag to the legacy location in the metadata which includes any value which was stored after the most recent replication involving the file. The system sends the metadata, which includes the grouping tag and any value stored at the legacy location in the metadata, to a destination node.

Abstract: Techniques are provided for incremental backup to an object store. A request may be received from an application to perform a backup from a volume hosted by a node to a backup target within the object store. A set of changed files within the volume since a prior backup of the volume was performed to the backup target is identified, along with metadata associated with the set of changed files. The metadata is utilized to identify changed data blocks comprising data of the set of changed files that was modified since the prior backup. The changed data blocks are backed up to the object store.

Abstract: Disclosed are techniques for deduplicating files to be ingested by a database. A bloom filter may be built for each of a first set of files to be ingested into a data exchange to generate a set of bloom filters, wherein the data exchange includes a metadata storage where metadata including a list of files ingested is stored. The set of bloom filters may be stored in the metadata storage of the data exchange. In response to receiving a set of candidate files to be ingested into the data exchange, the set of bloom filters may be used to identify from within the set of candidate files, each candidate file that is duplicative of a file in the first set of files.

Abstract: A computer system includes a NoSQL/SQL cluster and a distributed storage. In order to make storage target data redundant, a compute node in the NoSQL/SQL cluster instructs other compute nodes in the NoSQL/SQL cluster to write the storage target data into the distributed storage. As regards a file containing the storage target data, the compute node in the NoSQL/SQL cluster deduplicates data in storage apparatuses of a plurality of storage nodes in the distributed storage. The distributed storage performs erasure coding to store a file of the storage target data newly found to be duplicate in deduplication and to store a file of the storage target data not deduplicated in deduplication.

Abstract: Methods, apparatus, systems, architectures and interfaces for a wireless transmit receive unit (WTRU) performing a client-side edge resolution function (cERF) are provided. A method may include any of: determining a fully qualified domain name (FQDN) associated with a domain name server (DNS) request of an application associated with the WTRU; if the FQDN is associated with a valid edge instance (EI) record, selecting an EI for resolving the FQDN to an IP address; if the FQDN is not associated with a valid EI record: (1) transmitting a DNS query to a DNS server, (2) receiving an IP address associated with a selected EI to which the FQDN is resolved, and (3) updating the EI record with the IP address and the FQDN; and generating a traffic steering rule to re-direct uplink traffic associated with the application to the selected EI.

Abstract: A request to restore a primary system to a backed-up state of the primary system that is associated with a particular point in time is received at a storage system. The backed-up state of the primary system corresponds to a particular backup snapshot. The primary system is determined to be corrupted less than a threshold amount of corruption. An indication of a first set of changes that includes one or more changes to the primary system that have occurred since a last backup snapshot is received. A second set of changes that includes one or more changes between the particular backup snapshot and the last backup snapshot is determined. It is determined, based in part on the indication of the first set of changes, which data associated with the second set of changes to provide to the primary system. The determined data is provided to the primary system.

Abstract: Systems and methods for managing incremental data backups on an object store. A computing device receives first data representing a changed chunk of data in a revision of a data volume on a storage device, the changed chunk includes data having changes from previous data of a previous revision. The computing device creates a block of data representing a copy of the changed chunk on the object store, the object store also includes a previous revision block representing previous revision data. The computing device determines a previous index stored on the object store corresponding to the previous revision, which includes entries including at least one corresponding to the previous revision block. The computing device creates a copy of at least one previous index from the object store, and a revised index that updates the corresponding entry with updated entry data representing the change block.

Abstract: To manage expired backups in a storage system, a backup server retrieves multiple deletion logs which record invalid data included in one or more expired backups. When a deletion condition is met, the backup server identifies a first large object based on the multiple deletion logs, and sends a data migration request to an object-based storage system to instruct the object-based storage system to copy valid data of the first large object to a second large object. Thereafter, the backup server sends an object deletion request to the object-based storage system to instruct the object-based storage system to delete the first large object, thereby clearing up the expired backups.

Abstract: Embodiments of the present disclosure relate to a method for storage management, an electronic device, and a computer program product. According to an example implementation of the present disclosure, a method for storage management is provided, which comprises receiving an access request for target metadata from a user at a node among a plurality of nodes included in a data protection system, wherein the access request includes an identification of the target metadata; based on the identification, acquiring target access information corresponding to the identification from a set of access information for the user, wherein the target access information records information related to access to the target metadata; and if the target access information is acquired, determining the target metadata based on the target access information.

Abstract: One or more techniques and/or systems are provided for detecting stale data and/or changed data. For example, a bitmap file may be maintained and mapped to an inofile describing various states of files of a file system. The bitmap file may be populated with bitmap records indicating whether files were accessed, modified, or have other states. The bitmap file may efficiently convey information used to determine whether files have not been accessed recently (e.g., stale data) or were recently modified (e.g., changed data) compared to the inofile because the bitmap file may comprise a fraction of the size of the inofile (e.g., a byte of information may be used to represent various states of one or more files). In this way, instead of evaluating a relatively larger inofile, the bitmap file may be evaluated to efficiently identify stale data for deletion or destaging and/or changed data for backup.

Abstract: Systems and methods for maintaining and updating file system shadows by a synchronization client of a cloud-based platform. In some embodiments, an executor of the synchronization client can execute an action on an item in the local file system which changes the state of the item from an old state to a new state. The synchronization client updates the file system shadows with the new state of the item via an interface to facilitate generation of a synchronization event for the change to the item, that would otherwise go undetected if the change to the item was immediately reversed. In some embodiments, methods for providing shadow consistency and enhancing concurrent access to shadows are implemented by the synchronization client in maintaining and updating the file system shadows.

Abstract: Recovery points can be used for replicating a virtual machine and reverting the virtual machine to a different state. A filter driver can monitor and capture input/output commands between a virtual machine and a virtual machine disk. The captured input/output commands can be used to create a recovery point. The recovery point can be associated with a bitmap that may be used to identify data blocks that have been modified between two versions of the virtual machine. Using this bitmap, a virtual machine may be reverted or restored to a different state by replacing modified data blocks and without replacing the entire virtual machine disk.

Abstract: Application discovery from access patterns is disclosed. Access histories from multiple servers are collected and stored at a warehouse, which may be part of a data protection system. A time series analysis is performed on the access history to identify consistency groups and applications from the perspective of devices and storage arrays. Data protection operations such as backup operations can then be performed on the basis of devices or storage in storage arrays or other arrangements that pertain to specific consistency groups or to specific applications.

Abstract: A method that is performed for backing up data. The method includes obtaining, by a backup storage, an incremental backup request; and in response to the incremental backup request, identifying backup extents of a full backup associated with the incremental backup request using backup metadata; generating an intermediate backup file comprising the backup extents, wherein each of the backup extents is a reference to a correspond data block; obtaining modified data blocks from a production host; and updating the intermediate backup file using on the modified data blocks to generate a virtual synthetic backup file.

Abstract: A communication system that is capable of migrating setting values of different items from respective backup source apparatuses. The communication system includes a management apparatus that manages backup data of first and second backup source apparatuses, and a communication apparatus that communicates with the management apparatus. The management apparatus includes a processor that executes instructions to hold first backup data obtained from the first backup source apparatus, and hold second backup data obtained from the second backup source apparatus. The communication apparatus includes a processor that executes instructions to obtain a first setting value of a first item from the first backup data received from the management apparatus, obtain a second setting value of a second item that is different from the first item from the second backup data received from the management apparatus, and set up the first setting value and the second setting value.

Abstract: A method that is performed for backing up data. The method includes obtaining an incremental backup request; and in response to the incremental backup request: obtaining an asset and an asset entry associated with the incremental backup request; dividing the asset into pseudo-assets based on the asset entry; storing the pseudo-assets across backup storages to generate incremental pseudo-asset backups; initiating the merging of the incremental pseudo-asset backups to generate an incremental asset backup; and initiating the merging of the incremental asset backup with a previously generated full asset backup associated with the incremental backup request to generate a first synthetic full asset backup.

Abstract: According to certain embodiments, a provisioning manager comprises an interface and processing circuitry. The interface is configured to obtain provisioning data from a provisioning database. The processing circuitry is configured to prepare one or more configuration files based on the provisioning data. The configuration file(s) indicate how to provision one or more service instances. The processing circuitry is further configured to commit the configuration file(s) to one or more repositories in order to make the configuration file(s) available to at least one of the service instances. The processing circuitry is further configured to send one or more notifications indicating to one or more of the service instances that the configuration file(s) have been committed to the one or more repositories.

Abstract: Disclosed herein are methods, systems, and processes that can include performing a replication operation, receiving a backup operation instruction at a replication agent, and, in response to receipt of the backup operation instruction, performing an application quiescing operation and invoking an action of a backup agent. The replication operation sends data of an application executed by a virtual machine at a primary site, to a secondary site. The virtual machine is executed by a computing system at the primary site. The backup operation instruction is received from the backup agent. The application quiescing operation is performed by the replication agent. The application quiescing operation quiesces the replication operation, at least in part, by quiescing the application.

Abstract: Systems, methods, and computer media are described for storing and analyzing locally configured data. Both locally configured data and the corresponding data configurations are stored in a distributed storage platform (e.g., a blockchain). Using an accompanying data configuration to interpret and analyze stored data, accurate and meaningful local and global analyses can be performed, across data from different domains, without prior knowledge or external definition of the data. Storage in a distributed storage platform ensures that data cannot be modified and that all transactions are recorded. Example analyses that can be conducted on the stored locally configured data include audits, searching for variances, general queries for data having certain parameters or values, etc.

Abstract: Embodiments of method and system are directed to a best effort method to reconstruct corrupt files from available nodes or tiers and heal or repair the corrupt files within a cluster of nodes. The method looks for the existence of fingerprints of the lost segments in available tiers on the nodes or across nodes within a cluster. The method discovers the copies of these missing segments, creates an Lp tree referring these discovered segments and creates a virtual file in the namespace. The file is then moved to the destination tier where the corruption exists, thus healing the corruption.

Abstract: Data tags, such as may be used to classify data, can be automatically applied at appropriate times in a resource environment. A customer can provide an auto-tagging configuration file that can be used to determine tags to be applied to specific data objects based upon properties of those objects. The customer can also provide policies that indicate which actions can be performed for those objects based at least in part upon the applied tags. The tags can be automatically applied at any appropriate time, such as upon storage into the environment, upon modification of the auto-tagging configuration, or upon modification or the data object. In some embodiments, an auto-tagging process can also be performed in response to a request for access to the data object in order to ensure that the correct tags are applied before determining the permitted actions.

Abstract: Backup operations on selected directories are performed in a computing system. File system operations that impact the ability to backup the selected directories are failed while other file system operations are allowed. In particular, file system operations that would require a trawl of the selected directory in order to perform the backup operation are failed.

Abstract: Embodiments of the present disclosure provide a method, a device and a computer program product for data processing. The method comprises in response to data associated with an object being stored in the storage location, generating an entry indicating a first association relationship between the data and a storage location. The method further comprises generating metadata of the object, the metadata indicating a second association relationship between the object and the entry. Further, the method comprises in response to the first association relationship between the data and the storage location being changed, updating the entry independent of the metadata. Embodiments of the present disclosure may avoid the huge cost caused by changing metadata multiple times and reduce the system load and the impacts to the front end load.

Abstract: A unique identifier id(f) is generated for file f and stored on a content address server. A symmetric encryption key KF is generated for file f. File f is divided into n segments. A unique identifier id(si) is generated for each segment si. Each segment si of the n segments is encrypted using the symmetric key KF using a symmetric encryption algorithm, producing n encrypted segments esi. Each encrypted segment esi is stored with its identifier id(si) on the first peer device and at least one other peer device. For each encrypted segment esi, the identifier id(si) is stored on the content address server with the identifier id(f). A public key KU2 of a second user is retrieved, the symmetric key KF is encrypted with key KU2, producing wrapped key KW2=EAKU2(KF), and key KW2 is stored on the content address server with identifier id(f).

Abstract: A system indexes a first backup file, created for a data object when a first time period expired, in a first level of a data structure. The system indexes a second backup file, created for the data object when a second time period expired, in a second level of the data structure, the second time period being shorter than the first time period. The system receives a request to restore the data object to a specified time. The system enables restoration of the data object by identifying a first indexed backup file associated with the specified time in the first level of the data structure, by identifying a part of the second level of the data structure corresponding to the first indexed backup file, and by identifying a second indexed backup file associated with the specified time in the part of the second level of the data structure.

Abstract: In an executing database instance including a plurality of database nodes, creation of a backup of the executing database instance includes creation of a current savepoint in one of the plurality of database nodes by storing first modified pages of a cache of the database node in a datastore of the database node, transmitting a confirmation after storing the first modified pages, repeatedly identifying second modified pages of the cache and storing the identified second modified pages in the datastore, receiving an instruction to enter a critical phase and stopping the repeated identifying and storing in response to the instruction, blocking updates to the database node and transmitting a second confirmation, and receiving a second instruction and, in response to receiving the second instruction, identifying third modified pages of the cache and storing the third modified pages of the cache in the datastore.

Abstract: Embodiments are directed to managing data in a file system that includes storage nodes and storage volumes in a cloud computing environment (CCE). A backup job may be executed to perform further actions, including: providing a backup identifier that is associated with the backup job; determining the storage nodes based on the file system and the CCE; disabling the file system by disabling the storage nodes, wherein each disabled storage node is associated with a shutdown timestamp; determining storage volumes associated with each disabled storage node; and generating storage images that archive a copy of information from the storage volumes; associating the storage images with the backup identifier; confirming that the file system is consistent based on an absence of file system activity occurring subsequent to each shutdown timestamp; and enabling the file system by enabling the storage nodes.

Abstract: Disclosed herein are systems and method for method for predictive data protection. In one aspect, an exemplary method comprises selecting data stored on a computing device for backing up, according to a predetermined schedule for performing a backup; collecting features associated with the computing device where the data for the backup is stored, the features comprising device information for the computing device, user information for a user of the data, and external information associated with a locale of the computing device; analyzing the features to determine a set of backup parameters for the backup, wherein the backup parameters comprise scheduling parameters and destination storage parameters; generating a backup plan based on the set of parameters for performing the backup; and performing the backup of the data according to the backup plan.

Abstract: Data storage of workloads is migrated from a local computing environment to a cloud computing environment. The workloads are first executed in a runtime environment that have been deployed within a first virtual machine running in the local computing environment, according to a blueprint that defines a data storage path for the workloads. The data storage of the workloads is migrated by copying contents of a first file, which corresponds to a virtual disk of the first virtual machine, to a second file, modifying the blueprint to change the data storage path to a path that specifies a file path to the second file, and deploying a runtime environment within a second virtual machine running in the cloud computing environment, according to the modified blueprint. After transitioning the data storage of the workloads in this manner, the workloads are executed in the runtime environment deployed within the second virtual machine.

Abstract: An improved data replication system with goals of Recovery Point Objective of zero, meaning a zero potential for loss of data, and a Recovery Time Objective in the seconds, meaning very short downtime after a failure. The system includes duplicates of a data set preferably on multiple drives in multiple computers. Change requests are stored within duplicates, and when a change request has been stored in enough duplicates, it may be applied to any duplicate after all prior change requests have been applied to that duplicate. The system applies changes to duplicates of a data set in the same order. The system further includes a replicator operable to implement accessing and changing steps to meet the goals.

Abstract: A method of multilayer communication between a front-end application and at least one back-end includes receiving a message by a communication message broker that executes on a computer system from the front-end application, sending information of the message to an event bridge that executes on a computer system, parsing the information by the event bridge to determine at least one request, prompting a rules database by the event bridge to look up a rule, identifying the rule that applies to the at least one request by the rules database, processing the at least one request by the event bridge in response to the rule, sending the at least one processed request from the event bridge to a query application that executes on a computer system, and resolving at least one query by the query application to send at least one call to at least one back-end application.

Abstract: In one example, a method includes receiving, at a datacenter, a request from a client, where the request identifies a data range required by an application residing at the client, and the data range embraces less than all the contents of a file, backed up at the datacenter, with which the data range is associated. The example method further includes accessing the data in the data range, and transmitting data in the data range to the client, where the data transmitted to the client from the datacenter comprises respective portions of multiple incremental backups stored at the datacenter.

Abstract: An apparatus is configured to generate a current snapshot set for a consistency group comprising a plurality of storage volumes subject to replication from a source storage system to a target storage system, to compare one or more configuration attributes of the current snapshot set to one or more configuration attributes of a previous snapshot set generated for the consistency group, to detect a change in at least one configuration attribute of the current snapshot set relative to the previous snapshot set based at least in part on the comparing, and to communicate the detected change in the configuration attribute from the source storage system to the target storage system so as to permit the target storage system to implement a corresponding configuration update for the consistency group. The generating, comparing, detecting and communicating are illustratively performed as part of an ongoing asynchronous or synchronous replication process carried out between the source and target storage systems.

Abstract: Certain embodiments described herein relate to an improved block-level replication system. One or more components in an information management system may receive a request to perform a block-level replication between a source storage device and a destination storage device, and depending on the specific replication mode requested, (i) store block-level changes directly to the destination storage device or (ii) first to a recovery point store and then later to the destination storage device.

Abstract: A file is backed up to a backup system. A first cloud storage provided by a first cloud provider is connected to the backup system and the file is moved to the first cloud storage. Metadata is created at the backup system to reference the file moved to the first cloud storage. A second cloud storage is connected to the backup system. The file is moved from the first cloud storage to the second cloud storage. The metadata at the backup system is updated to reference the file now residing at the second cloud storage.

Abstract: Described in detail herein are systems and methods for managing single instancing data. Using a single instance database and other constructs (e.g. sparse files), data density on archival media (e.g. magnetic tape) is improved, and the number of files per storage operation is reduced. According to one aspect of a method for managing single instancing data, for each storage operation, a chunk folder is created on a storage device that stores single instancing data. The chunk folder contains three files: 1) a file that contains data objects that have been single instanced; 2) a file that contains data objects that have not been eligible for single instancing; and 3) a metadata file used to track the location of data objects within the other files. A second storage operation subsequent to a first storage operation contains references to data objects in the chunk folder created by the first storage operation instead of the data objects themselves.

Abstract: Recovery points can be used for replicating a virtual machine and reverting the virtual machine to a different state. A filter driver can monitor and capture input/output commands between a virtual machine and a virtual machine disk. The captured input/output commands can be used to create a recovery point. The recovery point can be associated with a bitmap that may be used to identify data blocks that have been modified between two versions of the virtual machine. Using this bitmap, a virtual machine may be reverted or restored to a different state by replacing modified data blocks and without replacing the entire virtual machine disk.

Abstract: A Data Storage Device (DSD) includes at least one non-volatile storage media. A command is received to modify a portion of a data object or file, with the command being byte-addressable for overwriting, deleting or adding the modified portion. The modified portion of the data object or file is written with an indication of a page container entry at a storage location in the at least one non-volatile storage media. The page container points to a previous storage location for previously written data for the data object or file that was most recently written before writing the modified portion. A mapping or data container entry in a container data structure is updated for the data object or file to point to the storage location storing the modified portion of the data object or file and the indication of the page container entry.

Abstract: A data storage system can scan one or more information stores of primary storage and analyze the metadata of files stored in the one or more information stores of primary storage to identify multiple, possibly relevant, secondary copy operations that can be performed on the files. The storage system can also identify primary storage usage information of each file during the scan and use that information to generate reports regarding the usage of the primary storage.

Abstract: Embodiments of the present disclosure provide a method and device for file backup and recovery. The method for file backup comprises receiving a file to be backed up and metadata describing an attribute of the file. The method further includes storing the metadata into a cache. The method further includes storing the file into a storage device for data backup. The method further includes receiving, from the storage device, information that indicates a storage position of the file in the storage device. Besides, the method further includes storing the information into the cache at an address that is determined based on the metadata.

Abstract: A method for a storage system reduces data movement for snapshot copy-on-write operations. The method includes providing a live volume having snapshot chunks. Each snapshot chunk includes a number of deduplication chunks. Each deduplication chunk is mapped to a disk chunk on a disk. The method includes creating a snapshot of the live volume and, for each host write to a snapshot chunk of the live volume that shares a set of disk chunks with a snapshot, performing a snapshot copy-on-write operation by a using a deduplication operation.

Abstract: Disclosed are systems and methods for using a metadata agent to collect metadata from a client computer system and including receiving the metadata associated with files used by applications executing in the client computer system. The metadata belong to objects stored in a volume associated with the client computer system. The metadata is collected in real time by the metadata agent executing in the client computer system as a background task. The metadata is stored in a metadata base associated with a metadata server. A request to search the metadata is received from a backup server associated with the metadata server. The search request includes search criteria. A search engine associated with the metadata server searches the metadata in the metadata database to find a match based on the search criteria. A search result is transmitted from the metadata server to the backup server which uses the search result to search for objects in the backup data.

Abstract: In one example, a method includes receiving, from a client, a request for file system information, transmitting the requested file system information to the client, receiving, from the client, a request for data that includes a portion of a file that resides at the datacenter, where the file is compatible for use by an application residing at the client, where the request for data specifies a particular byte range associated with the file, and where the byte range spans a group of different backups of a baseline dataset residing at the datacenter. The example method further includes creating a virtual synthetic that is formed by the data in the requested byte range and includes respective portions of data from each of the group of backups residing at the datacenter, and transmitting the virtual synthetic to the client.

Abstract: A disaster recovery process and solution for a master routing server can utilize replicate servers to generate efficiencies when a failure occurs. A voice over Internet protocol (VoIP) platform can utilize the master routing server for customer call flow and feature provisioning. Back-up data can be stored at a cloud-based data store and sent to a replicate server that has been promoted in response to a failure being determined to have occurred. Additionally, the master routing server can receive and maintain a master provisioning database and send that database to the replicate routing servers for the purpose of properly routing call flows.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for incremental backup. The method comprises receiving a set of file paths to be backed up and parsing each file path in the set of file paths to construct a prefix tree. The method further comprises traversing the prefix tree to read an ordered set of file paths in the prefix tree and performing an incremental backup sequentially according to the ordered set of file paths. Embodiments of the present disclosure sort a set of file paths to be backed up using a prefix tree that shares common path prefixes. Thus, embodiments of the present disclosure can achieve fast sort of the set of file paths, and can effectively save storage space needed for sorting a considerable number of file paths in the memory, thereby reducing the times of comparing file names when sorting file paths.

Abstract: The disclosure generally describes methods, software, and systems, including a method for publishing messages through a messaging client of a database server. A message to be published to one or more message brokers is received at a server and from a database client. The message is in the form of a SQL statement. The received message is processed at the server. Message broker configurations associated with the received message are determined. The message is published to the one or more message brokers by invoking a messaging client at the server and using at least the message broker configurations.

Abstract: A backup, search, and restore service is provided. The service can be achieved through a backup system, and a search and restore server. A user can be enabled to initiate a search request for one or more data items. A search can be performed by the search and restore server using metadata for the data items backed up by the backup system to return the one or more data items. The metadata for the data items can be generated by the backup system when data items are backed up by the backup system. The backup system may back up the data items on an incremental basis. The user can be enabled to select a data item in the one or more data items for restoration on the data system. Header information of the selected data item can be obtained from the data system to determine whether the restoration is necessary.

Abstract: Techniques described and suggested herein include observing, monitoring and storing sequence data and lag data associated with write and read operations between an application and a service, such as a service provided by a computing resource service provider, so as to simulate or otherwise derive consistency behavior observed therewith. The sequence data and/or lag data may be used to configure a service, such as a mock service similar to the observed service, to respond in a fashion similar to the previously monitored service.

Abstract: Recovery points can be used for replicating a virtual machine and reverting the virtual machine to a different state. A filter driver can monitor and capture input/output commands between a virtual machine and a virtual machine disk. The captured input/output commands can be used to create a recovery point. The recovery point can be associated with a bitmap that may be used to identify data blocks that have been modified between two versions of the virtual machine. Using this bitmap, a virtual machine may be reverted or restored to a different state by replacing modified data blocks and without replacing the entire virtual machine disk.