Abstract: A system manages a log-structured file system (LFS) by: receiving an input/output (I/O) operation for the LFS, the I/O operation prompting a key to be added to a first node of a tree metadata structure, the tree mapping addresses in a first address space to addresses in a second address space; determining that addition of the key to the first node would exceed a maximum number of keys allowed in the first node; adding a second node to the tree based on the determining, the second node containing the key; moving a quantity of keys from the first node to the second node such that a total number of keys resulting in the second node is less than half of the maximum number of keys, minus one, configured to be stored in nodes of the LFS; and writing updates to the tree metadata structure within the LFS.

Abstract: An example method for a first host, being an owner of an object stored in a virtual storage area network (vSAN) cluster, to perform encryption and decryption operations during a rekey in the vSAN cluster is disclosed. The method includes obtaining a first encryption key and a first key identifier (ID) of the first encryption key; transmitting the first key ID and an active key index to a second host; using the first encryption key to perform encryption and decryption operations; and in response to a determination of receiving a key change notification from a master node of the vSAN cluster, terminating a connection with the second host.

Abstract: System and method for managing distributed storage objects for host unavailability in a distributed storage system uses at least one of a crash indicator in a specific on-disk block and a paused object indicator for a distributed storage object to determine whether to perform data recovery for the distributed storage object. When the crash indicator is set or the paused object indicator implies that the distributed storage object is a paused object, the distributed storage object is left as a paused object without perform the data recovery for the distributed storage object. When the crash indicator is unset and the paused object indicator implies that the distributed storage object is not a paused object, the data recovery for the distributed storage object is performed.

Abstract: Techniques for recovering metadata associated with data backed up in cloud object storage are provided. In one set of embodiments, a computer system can create a snapshot of a data set, where the snapshot includes a plurality of data blocks of the data set that have been modified since the creation of a prior snapshot of the data set. The computer system can further upload the snapshot to a cloud object storage platform of a cloud infrastructure, where the snapshot is uploaded as a plurality of log segments conforming to an object format of the cloud object storage platform, and where each log segment includes one or more data blocks in the plurality of data blocks, and a set of metadata comprising, for each of the one or more data blocks, an identifier of the data set, an identifier of the snapshot, and a logical block address (LBA) of the data block.

Abstract: An example method for a first host, being an owner of an object stored in a virtual storage area network (vSAN) cluster, to perform encryption and decryption operations during a rekey in the vSAN cluster is disclosed. The method includes obtaining a first encryption key and a first key identifier (ID) of the first encryption key; transmitting the first key ID and an active key index to a second host; using the first encryption key to perform encryption and decryption operations; and in response to a determination of receiving a key change notification from a master node of the vSAN cluster, terminating a connection with the second host.

Abstract: In one set of embodiments, a computer system can create a snapshot of a data set, where the snapshot includes a plurality of data blocks of the data set. The computer system can upload the snapshot to a cloud object storage platform of a cloud infrastructure, where the snapshot is uploaded as a plurality of log segments conforming to an object format of the cloud object storage platform, and where each log segment includes one or more data blocks in the plurality of data blocks, and a set of metadata comprising, for each of the one or more data blocks, an identifier of the data set, an identifier of the snapshot, and a logical block address (LBA) of the data block. The computer system can then communicate the set of metadata to a server component running in a cloud compute and block storage platform of the cloud infrastructure.

Abstract: Examples provide a method of communication between a client driver and a filesystem server. The client driver executes in a virtual machine (VM) and the filesystem server executes in a hypervisor. The method includes: allocating, by the client driver, shared memory in an address space of the VM for the communication; sending identification information for the shared memory from the client driver to the filesystem server through an inter-process communication channel between the client driver and the filesystem server; identifying, by the filesystem server in cooperation with a kernel of the hypervisor, the shared memory within an address space of the hypervisor, based on the identification information, to create a shared memory channel; sending commands from the client driver to the filesystem server through the shared memory channel; and receiving completion messages for the commands from the filesystem server to the client driver through the shared memory channel.

Abstract: The present disclosure is related to methods, systems, and machine-readable media for supporting deduplication in file storage using file chunk hashes. A hash of a chunk of a log segment can be received from a software defined data center. A chunk identifier can be associated with the hash in a hash map that stores associations between sequentially-allocated chunk identifiers and hashes. The chunk identifier can be associated with a logical address corresponding to the chunk of the log segment in a logical map that stores associations between the sequentially-allocated chunk identifiers and logical addresses. A search of the hash map can be performed to determine if the chunk is a duplicate, and the chunk can be deduplicated responsive to a determination that the chunk is a duplicate.

Abstract: Solutions for managing archived storage include receiving, at a first node, a snapshot comprising object data (e.g., a virtual machine disk snapshot) from a second node (e.g., a software defined data center), and storing the snapshot in a tiered structure that includes a data tier and a metadata tier. Snapshots may be used for fail-over operations and/or backups, to support disaster recovery. The data tier comprises a log-structured file system (LFS), and the metadata tier comprises a content addressable storage (CAS) identifying addresses within the LFS. The metadata tier also comprises a logical layer indicating content in the CAS. Segment cleaning of the data tier is performed using a segment usage table (SUT). Some examples include performing a fail-over operation from the second node to a third node using at least the stored snapshot for workload recovery. In some examples, the CAS comprises a log-structured merge-tree (LSM-tree).

Abstract: The present disclosure is related to methods, systems, and machine-readable media for supporting deduplication in object storage using subset hashes. A plurality of hashes of a plurality of blocks of a plurality of log segments can be received from a software defined data center, wherein each block corresponds to a respective logical address. Each of the plurality of logical addresses can be associated with a respective sequentially-allocated chunk identifier in a logical map. A subset hash comprising a hash of a subset of the plurality of blocks can be determined that corresponds to a contiguous range of the plurality of logical addresses. A search of a hash map for the subset hash can be performed to determine if the subset hash is a duplicate. The subset of the plurality of blocks can be deduplicated responsive to a determination that the subset hash is a duplicate.

Abstract: Techniques for the increased efficiency of storing data objects storage in the object storage of a software designed data center (SDDC) are provided. The techniques include the efficient storage of data, while enabling snapshots of each updating of the data. The snapshots of the data may be efficiently recovered via the techniques. Difference-level mappings for each snapshot are encoded in compact self-balancing data trees included in the object's metadata. The metadata mappings include mappings between various address spaces employed by the SDDC, as well as the address spaces employed by data stores that store the data on physical medium. Because the metadata is efficiently structured, the metadata for an object may be cached for quick lookups during data access and/or snapshot recovery. The techniques also provide low-latency recovery and/or system rollback in the event of any failure in the SDDC.

Abstract: Techniques for the increased efficiency of storing data objects storage in the object storage of a software designed data center (SDDC) are provided. The techniques include the efficient storage of data, while enabling snapshots of each updating of the data. The snapshots of the data may be efficiently recovered via the techniques. Difference-level mappings for each snapshot are encoded in compact self-balancing data trees included in the object's metadata. The metadata mappings include mappings between various address spaces employed by the SDDC, as well as the address spaces employed by data stores that store the data on physical medium. Because the metadata is efficiently structured, the metadata for an object may be cached for quick lookups during data access and/or snapshot recovery. The techniques also provide low-latency recovery and/or system rollback in the event of any failure in the SDDC.

Abstract: Techniques for tiering data to a cold storage tier of a cloud object storage platform are provided. In one set of embodiments, a computer system can identify one or more old snapshots of a data set that reside in a first storage tier of the cloud object storage platform, where the one or more old snapshots are snapshots that are unlikely to be deleted from the cloud object storage platform within a period of N days. The computer system can further, for each snapshot in the one or more old snapshots: identify one or more data blocks in the snapshot that are superseded by a more recent snapshot in the one or more old snapshots; write the one or more data blocks to a second (i.e., cold) storage tier of the cloud object storage platform that has a lower storage cost than the first storage tier; and cause the one or more data blocks to be deleted from the first storage tier.

Abstract: The present disclosure is related to methods, systems, and machine-readable media for supporting deduplication in object storage using subset hashes. A plurality of hashes of a plurality of blocks of a plurality of log segments can be received from a software defined data center, wherein each block corresponds to a respective logical address. Each of the plurality of logical addresses can be associated with a respective sequentially-allocated chunk identifier in a logical map. A subset hash comprising a hash of a subset of the plurality of blocks can be determined that corresponds to a contiguous range of the plurality of logical addresses. A search of a hash map for the subset hash can be performed to determine if the subset hash is a duplicate. The subset of the plurality of blocks can be deduplicated responsive to a determination that the subset hash is a duplicate.

Abstract: The present disclosure is related to methods, systems, and machine-readable media for supporting deduplication in file storage using file chunk hashes. A hash of a chunk of a log segment can be received from a software defined data center. A chunk identifier can be associated with the hash in a hash map that stores associations between sequentially-allocated chunk identifiers and hashes. The chunk identifier can be associated with a logical address corresponding to the chunk of the log segment in a logical map that stores associations between the sequentially-allocated chunk identifiers and logical addresses. A search of the hash map can be performed to determine if the chunk is a duplicate, and the chunk can be deduplicated responsive to a determination that the chunk is a duplicate.

Abstract: Techniques for recovering metadata associated with data backed up in cloud object storage are provided. In one set of embodiments, a computer system can create a snapshot of a data set, where the snapshot includes a plurality of data blocks of the data set that have been modified since the creation of a prior snapshot of the data set. The computer system can further upload the snapshot to a cloud object storage platform of a cloud infrastructure, where the snapshot is uploaded as a plurality of log segments conforming to an object format of the cloud object storage platform, and where each log segment includes one or more data blocks in the plurality of data blocks, and a set of metadata comprising, for each of the one or more data blocks, an identifier of the data set, an identifier of the snapshot, and a logical block address (LBA) of the data block.

Abstract: Techniques for tiering data to a cold storage tier of a cloud object storage platform are provided. In one set of embodiments, a computer system can identify one or more old snapshots of a data set that reside in a first storage tier of the cloud object storage platform, where the one or more old snapshots are snapshots that are unlikely to be deleted from the cloud object storage platform within a period of N days. The computer system can further, for each snapshot in the one or more old snapshots: identify one or more data blocks in the snapshot that are superseded by a more recent snapshot in the one or more old snapshots; write the one or more data blocks to a second (i.e., cold) storage tier of the cloud object storage platform that has a lower storage cost than the first storage tier; and cause the one or more data blocks to be deleted from the first storage tier.

Abstract: Solutions for managing archived storage include receiving, at a first node, a snapshot comprising object data (e.g., a virtual machine disk snapshot) from a second node (e.g., a software defined data center), and storing the snapshot in a tiered structure that includes a data tier and a metadata tier. Snapshots may be used for fail-over operations and/or backups, to support disaster recovery. The data tier comprises a log-structured file system (LFS), and the metadata tier comprises a content addressable storage (CAS) identifying addresses within the LFS. The metadata tier also comprises a logical layer indicating content in the CAS. Segment cleaning of the data tier is performed using a segment usage table (SUT). Some examples include performing a fail-over operation from the second node to a third node using at least the stored snapshot for workload recovery. In some examples, the CAS comprises a log-structured merge-tree (LSM-tree).

Abstract: Examples provide a method of communication between a client driver and a filesystem server. The client driver executes in a virtual machine (VM) and the filesystem server executes in a hypervisor. The method includes: allocating, by the client driver, shared memory in an address space of the VM for the communication; sending identification information for the shared memory from the client driver to the filesystem server through an inter-process communication channel between the client driver and the filesystem server; identifying, by the filesystem server in cooperation with a kernel of the hypervisor, the shared memory within an address space of the hypervisor, based on the identification information, to create a shared memory channel; sending commands from the client driver to the filesystem server through the shared memory channel; and receiving completion messages for the commands from the filesystem server to the client driver through the shared memory channel.

Abstract: A method for managing metadata for data stored in a cloud storage is provided. The method receives, at a first of a plurality of metadata servers, information associated with an object stored in the cloud storage, the information comprising a plurality of LBAs for where the object is stored. Each metadata server allocates contiguous chunk IDs for a group of objects. The method generates a new chunk ID for the object, which is a combination of a unique fixed value and a monotonically incrementing local value associated with each LBA, such that a first LBA is mapped to a first chunk ID having a first local value and a next LBA is mapped to a second chunk ID having the first local value incremented as a second local value. The method stores the new chunk ID and other metadata in one or more tables stored in a metadata storage.