Abstract: A system can determine to write a data object to a storage system that implements an append-only write policy to data chunks. The system can divide a data chunk of the data chunks into a number of data segments. The system can divide respective data segments of the number of data segments into respective stripes. The system can write a first portion of data of the data object to first stripes of the respective stripes. The system can, after writing the first portion of data of the data object to the first stripes, and independently of writing a second portion of data of the data object to second stripes of the respective stripes, determine erasure coding values, and write respective erasure coding values of the erasure coding values to respective erasure coding stripes that are separate from the respective stripes, The system can store the data chunk.

Abstract: Storage systems are disclosed. For instance, a storage system comprises a first storage device of a first type and a second storage device of a second type, and the first storage device has a higher access velocity than the second storage device. A threshold indicating a volume limit of data stored in the first storage device can be determined. Data, which is specified by a write request for writing data to the storage system, is written to the first storage device in response to determining the data amount in the first storage device is lower than the threshold. A read request from a client device is processed based on data stored in the first storage device. Consequently, the first storage device with a higher access velocity in the storage system may be utilized as much as possible, so that storage device latency in the storage system is managed more effectively.

Abstract: Obtaining or facilitating obtaining statistical performance of a storage system is described. For instance, a method comprises: dividing a value range of performance of a storage system into a plurality of adjacent sub-ranges, an upper limit value of each sub-range being a predetermined multiple of a non-zero lower limit value of the sub-range. The method also comprises: determining a distribution of a plurality of measurement values of the performance among the plurality of sub-ranges. The method further comprises: estimating, based on the distribution, a percentile of the plurality of measurement values corresponding to a predetermined percentage to indicate statistical performance of the storage system. As a result, statistical performance indicators of the storage system can be obtained with an acceptable error using a small amount of memory resources.

Abstract: Storage systems are disclosed. For instance, a storage system comprises a first storage device of a first type and a second storage device of a second type, and the first storage device has a higher access velocity than the second storage device. A threshold indicating a volume limit of data stored in the first storage device can be determined. Data, which is specified by a write request for writing data to the storage system, is written to the first storage device in response to determining the data amount in the first storage device is lower than the threshold. A read request from a client device is processed based on data stored in the first storage device. Consequently, the first storage device with a higher access velocity in the storage system may be utilized as much as possible, so that storage device latency in the storage system is managed more effectively.

Abstract: Storage systems are disclosed. For instance, a storage system comprises a first storage device of a first type and a second storage device of a second type, and the first storage device has a higher access velocity than the second storage device. A threshold indicating a volume limit of data stored in the first storage device can be determined. Data, which is specified by a write request for writing data to the storage system, is written to the first storage device in response to determining the data amount in the first storage device is lower than the threshold. A read request from a client device is processed based on data stored in the first storage device. Consequently, the first storage device with a higher access velocity in the storage system may be utilized as much as possible, so that storage device latency in the storage system is managed more effectively.

Abstract: Obtaining or facilitating obtaining statistical performance of a storage system is described. For instance, a method comprises: dividing a value range of performance of a storage system into a plurality of adjacent sub-ranges, an upper limit value of each sub-range being a predetermined multiple of a non-zero lower limit value of the sub-range. The method also comprises: determining a distribution of a plurality of measurement values of the performance among the plurality of sub-ranges. The method further comprises: estimating, based on the distribution, a percentile of the plurality of measurement values corresponding to a predetermined percentage to indicate statistical performance of the storage system. As a result, statistical performance indicators of the storage system can be obtained with an acceptable error using a small amount of memory resources.

Abstract: Storage systems are disclosed. For instance, a storage system comprises a first storage device of a first type and a second storage device of a second type, and the first storage device has a higher access velocity than the second storage device. A threshold indicating a volume limit of data stored in the first storage device can be determined. Data, which is specified by a write request for writing data to the storage system, is written to the first storage device in response to determining the data amount in the first storage device is lower than the threshold. A read request from a client device is processed based on data stored in the first storage device. Consequently, the first storage device with a higher access velocity in the storage system may be utilized as much as possible, so that storage device latency in the storage system is managed more effectively.