Systems and methods to manage write commands in a cache

摘要

When a virtual machine sends a write command to a host operating system, a cache system stores the record included in the write command and later sends the write command to a storage system. Systems and methods store an indication of when the write command was received along with the received records in the cache. The cache system determines an order of the records from the indication. In some instances, records received at the same time are serialized and/or assigned record numbers. The simultaneously received records can be assigned a batch number. According to the determined order, the records are retrieved from the cache memory and included in write commands sent to the storage system. In some instances, checkpoints can be stored to prevent records from being re-sent to the storage system following a failure.

主权项

1. A method comprising:
receiving a first write command sent from a virtual machine to a host operating system running on a computing system, the first write command instructing a storage system to store a first record at a first storage system memory location; storing the first record at a first location in a storage cache with an indication of when the first write command was received; receiving a second write command sent from the virtual machine to the host operating system running on the computing system, the second write command instructing the storage system to store a second record at the first storage system memory location; storing the second record at a second location in the storage cache with an indication of when the second write command was received; determining an order of the first record and the second record based on the stored indication of when the first write command was received and the stored indication of when the second write command was received; based on the determined order, retrieving the first record from the first cache location and sending the first write command to the storage system, and then retrieving the second record from the second cache location and sending the second write command to the storage system; simultaneously receiving a third write command and a fourth write command sent from the virtual machine to the host operating system running on the computing system, the third write command instructing the storage system to store a third record and the fourth write command instructing the storage system to store a fourth record; storing the third record at a third location in the cache storage with an indication of when the third write command was received; storing the fourth record at a fourth location in the cache storage with an indication that the fourth write command was received after the third write command was received; determining an order of the third record and the fourth record based on the stored indication of when the third write command was received and the stored indication of when the fourth write command was received; and based on the determined order of the third record and the fourth record, retrieving the third record from the third cache location and sending the third write command to the storage system, and then retrieving the fourth record from the fourth cache location and sending the fourth write command to the storage system.