Abstract: Techniques to achieve high availability in a multi-controller system are disclosed. In various embodiments, an indication is received that a network ping-based heartbeat mechanism has failed. In response to said indication, an alternative heartbeat is provided at least in part by periodically updating a heartbeat data stored in an on-disk heartbeat data structure, in a portion of a disk that is available to both an active controller and a standby controller of the multi-controller system.

Abstract: Optimized remoting cloning is disclosed, including: receiving data from a source storage system associated with an ongoing replication process of a snapshot; and prior to the completion of the replication process of the snapshot, generating a set of metadata associated with a clone of the snapshot, wherein at least a portion of data comprising the snapshot that has been received at the destination storage system can be read using the clone while the replication process of the snapshot is ongoing.

Abstract: Recovery of an in-memory state in a log-structured filesystem using fuzzy checkpoints is disclosed, including: determining a portion of a data structure to checkpoint to a storage unit, wherein the structure is associated with a set of references to locations in persistent storage at which metadata is stored, wherein the portion of the data structure is dynamically determined based at least in part on a size of the data structure and a predetermined number of storage units to be associated with a checkpoint window, wherein the number of storage units to be associated with the checkpoint window is fewer than a total number of storage units associated with the persistent storage; and checkpointing the portion of the data structure to the storage unit.

Abstract: Storage management is disclosed, including: causing at least a control portion of a virtual disk to be created for a virtual machine; and using the at least control portion of the virtual disk as a communication channel between the virtual machine and a storage system.

Abstract: Efficient use of spare device(s) associated with a group of devices is disclosed, including: receiving a set of data; storing the set of data across a group of devices according to a protocol; determining a set of additional data units associated with the set of data; and storing the set of additional data units in a spare device associated with the group of devices, wherein the spare device is available to be used in the event of a failure of a device included in the group of devices, including by overwriting the set of additional data units as needed.

Abstract: Optimized remoting cloning is disclosed, including: receiving data from a source storage system associated with an ongoing replication process of a snapshot; and prior to the completion of the replication process of the snapshot, generating a set of metadata associated with a clone of the snapshot, wherein at least a portion of data comprising the snapshot that has been received at the destination storage system can be read using the clone while the replication process of the snapshot is ongoing.

Abstract: Avoiding long access latencies in redundant storage systems is disclosed, including: determining a first device associated with a request is in a slow access period based at least in part on a scheduled slow access period, wherein the first device is included in a plurality of devices associated with a redundant storage system; and reconstructing data associated with the request from one or more devices included in the plurality of devices other than the first device.

Abstract: Performing data synchronization is disclosed, including: receiving an indication to synchronize a container to a snapshot, wherein the container has a first data state and an identity, wherein the snapshot corresponds to a second data state; causing the container to have the second data state corresponding to the snapshot; and maintaining the identity of the container.

Abstract: Synchronizing data is disclosed, including: generating a snapshot index associated with a first set of data; generating a set of difference data between a snapshot index associated with a second set of data and the snapshot index associated with the first set of data; and applying the set of difference data to a set of metadata associated with the first set of data, wherein the set of metadata reflects a current state of the first set of data.

Abstract: Synchronizing data is disclosed, including: generating a snapshot index associated with a first set of data; generating a set of difference data between a snapshot index associated with a second set of data and the snapshot index associated with the first set of data; and applying the set of difference data to a set of metadata associated with the first set of data, wherein the set of metadata reflects a current state of the first set of data.

Abstract: Avoiding long access latencies in redundant storage systems is disclosed, including: determining a first device associated with a request is in a slow access period; and reconstructing data associated with the request from one or more other devices comprising a redundant storage system in which the first device and the one or more other devices are included.

Abstract: Storing data that includes receiving an indication to perform an operation with respect to data associated with a virtual machine storage abstraction; and using a meta information identifying which data stored on a storage system is associated with the virtual machine storage abstraction to perform the requested operation.

Abstract: Storing data is disclosed, including: receiving a request to create a clone of a snapshot included in a first set of metadata associated with a source data; and generating a second set of metadata for the clone, wherein the second set of metadata associated with the clone includes, for at least some metadata values, a data associating with the second set of metadata one or more corresponding values in the first set of metadata associated with the source data.

Abstract: Automatically aligning virtual blocks of partitions to blocks of underlying physical storage is disclosed. In some embodiments, a starting offset of a partition included in a logical container is detected. In some embodiments, a misalignment correction amount for a partition included in a logical container is detected. In some embodiments, a misalignment associated with a partition included in a logical container is corrected.

Abstract: Storing data that includes receiving an indication to perform an operation with respect to data associated with a virtual machine storage abstraction; and using a meta information identifying which data stored on a storage system is associated with the virtual machine storage abstraction to perform the requested operation.

Abstract: Avoiding long access latencies in redundant storage systems is disclosed, including: determining a first device associated with a request is in a slow access period; and reconstructing data associated with the request from one or more other devices comprising a redundant storage system in which the first device and the one or more other devices are included.

Abstract: Automatically aligning virtual blocks of partitions to blocks of underlying physical storage is disclosed. In some embodiments, a starting offset of a first partition included in a logical container is detected. In some embodiments, a misalignment correction amount for a first partition included in a logical container is detected. In some embodiments, a misalignment associated with a first partition included in a logical container is corrected.

Abstract: A data storage system is disclosed, including: a first storage device of a first storage device type, a second storage device of a second storage device type, and a processor configured to implement a hybrid file system configured to store each of a plurality of data values in at least a corresponding primary location, which for a given data value may be in either the first storage device or the second storage device; wherein the hybrid file system is configured to use a first access approach optimized based on a first access attribute of the first storage device type to interact with the first storage device and a second access approach optimized based on a second access attribute of the second storage device type to interact with the second storage device.