Vmware, Inc.

Vivek Patidar

Pradeep H Krishnamurthy

Prasanth Jose

Asit Desai

Prasanna Aithal

Mahesh Shivanagouda Hiregoudar

Prasad Rao Jangam

Srinivasa Shantharam

Bryan Branstetter

Gurudutt Kumar Vyudayagiri Jagannath

Raghavan Pichai

Gurudutt Kumar

The disclosure provides for fault tolerant parallel journaling that speeds up both input/output (I/O) operations and recovery operations. Journal entry writing may occur in parallel with data writing operations. Even if a crash occurs during a data writing operation for which the journal entry has been written, the recovery operation will correctly determine that the journal entry is not valid. Additionally, recovery operations may need to validate fewer journal entries, and yet possibly retain more valid data. Examples include: for each of a plurality of journal entries: receiving incoming data; determining a signature for the incoming data; generating the journal entry for the incoming data; writing the signature in the journal entry; and writing the journal entry and the incoming data to a storage media; and based at least on writing data to the storage media, updating an awaiting index in a journal header.

Fault tolerant parallel journaling for file systems

The disclosure supports both trickle and burst input/output (I/O) admission rates in journaling file systems. Examples include receiving incoming data; based at least on receiving the incoming data, generating metadata for a journal entry; adding the metadata to an active metadata batch; issuing a data write to write the incoming data to a storage medium; monitoring for a first trigger comprising determining that a data write for an entry in the active metadata batch is complete; based at least on the first trigger, closing the active metadata batch; and issuing a journal write to write entries of the active metadata batch to the storage medium. A second trigger comprises determining that a batch open time exceeds a selected percentage of a moving average of data write durations. A third trigger comprises determining that a batch counter exceeds a count threshold. These triggers work together to reduce I/O latencies.

Adaptive metadata batching based on input/output rate

System and method for executing a file system operation for a computer system utilize a computed hash value of a file system object to access a hash block of a file system directory stored in a storage system to locate a hash slot corresponding to the computed hash value. Using at least one of a hash pointer in the hash slot and an allocation block of the file system directory, a dirent slot in a dirent block of the file system directory is located to perform an operational task on the particular dirent slot to execute the file system operation.

Hash-based file system

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Bengaluru, India

Vivek Patidar