Pavilion Data Systems, Inc.

Pavillon Data Systems, Inc.

Pavilion Data System, Inc.

Sundar Kanthadai

Karagada Ramarao Kishore

Kiron Balkrishna Malwankar

Venkeepuram R Satish

Unmesh Rathi

Ray Siruno

Eugene Fleisher

Sandeep Dhavale

Vaibhav Nipunage

Implementations for dropped write detection and correction are described. An example method includes receiving a write command comprising data and associated metadata; increasing a value of a monotonic counter; generating updated metadata by adding the counter value to the metadata; atomically writing (a) the data and a first instance of the updated metadata to a first storage device, and (b) a second instance of the updated metadata to a second storage device; receiving a read request for the data; reading the first instance of the updated metadata from the first storage device; reading the second instance of the updated metadata from a second storage device; comparing the instances of metadata and the counter values within each instance of metadata; determining whether the first counter value matches the second counter value; and determining whether a dropped write has occurred based on whether the first counter values matches the second counter value.

Dropped write detection and correction

A storage server includes a plurality of solid state drives (SSDs), a plurality of input/output (IO) controllers, and a plurality of fabrics. Each fabric is configured to provide a fully connected mesh topology that connects each of the plurality of IO controllers to each of the plurality of SSDs. Each fabric comprises a management controller, a first switch layer comprising a first plurality of switches coupled to the plurality of IO controllers, and a second switch layer comprising a second plurality of switches coupled to a) the first plurality of switches and b) the plurality of SSDs, The first switch layer and the second switch layer together provide the fully connected mesh topology that connects every IO controller of the plurality of IO controllers to every SSD of the plurality of SSDs.

High availability storage system

A processing device receives a request from a remote computing device to read data from a virtual storage device. The processing device identifies a physical storage device to be accessed to satisfy the request. The processing device then sends a sub-request to the physical storage device to access a portion of the physical storage device. Responsive to determining that the physical storage device has not returned a response to the sub-request within a latency threshold time associated with the physical storage device, the processing device initiates recovery of the portion of the physical storage device to recompute contents of the portion of the physical storage device. The processing device then returns a response to the request from the remote computing device.

Consistent latency for solid state drives

A storage server comprises a plurality of storage devices arranged in a redundant storage array and a plurality of controllers. One of the controllers determines that a storage device in the redundant storage array has failed, determines a first portion of the storage device to be recovered by a first controller and determines a second portion of the storage device to be recovered by a second controller. The first controller recovers the first portion of the storage device and the second controller recovers the second portion of the storage device.

Distributed rebuild of failed storage device

A processing device of a storage server that manages a plurality of SSDs receives to read data. The processing device determines a first SSD of the plurality of SSDs on which the data is stored, and determines that the first SSD is performing a background operation. The processing device determines whether the data is located on a block of the first SSD that will be unavailable during the background operation. Responsive to determining that the data is located on the block of the first SSD, the processing device reconstructs the data based on additional data on one or more remaining SSDs of the plurality of SSDs. The processing device then generates a response to the request that includes the data.

Proactive scheduling of background operations for solid state drives

A processing device of a storage server that manages a plurality of SSDs receives a request to write data. The processing device determines one or more attributes associated with the request, generates a stream tag for the request based on the one or more attributes, and sends a first write command to a first SSD of the plurality of SSDs. The first write command comprises at least a portion of the data and the stream tag that causes the first SSD to write the portion of the data to a first stream block of the first SSD.

Streams across multiple controllers to improve solid state drive performance

A processing device of a storage server receives a write request to write to a first logical address of a virtual storage device that is mapped to a plurality of SSDs. The processing device stores a data block associated with the request in a buffer, stores an entry for the write request in a queue, the entry comprising a reference to the data block in the buffer, sends a write command to an SSD, the write command comprising the data block, and subsequently receives an acknowledgment that the data block has been written to the SSD. The processing device maintains the data block in the buffer until a combined size of a plurality of data blocks in the buffer is equal to or greater than a threshold, the threshold being based on a number of SSDs in the plurality of SSDs and a block size of the plurality of SSDs.

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Fremont, CA, United States of America

Sundar Kanthadai