摘要:
An I/O hint framework is provided. In one embodiment, a computer system can receive an I/O command originating from a virtual machine (VM), where the I/O command identifies a data block of a virtual disk. The computer system can further extract hint metadata from the I/O command, where the hint metadata includes one or more characteristics of the data block that are relevant for determining how to cache the data block in a flash storage-based cache. The computer system can then make the hint metadata available to a caching module configured to manage the flash storage-based cache.
摘要:
Techniques for managing space in a flash storage-based cache are provided. In one embodiment, a computer system can calculate “ratio of effective cache space” (rECS) values for a plurality of VMs, where each VM has a cache allocation comprising a subset of a global pool of cache blocks in the flash storage-based cache, and where the rECS value for the VM indicates a proportion of the subset that has been populated with cached data and re-accessed by the VM within a current time window. The computer system can further determine a new cache allocation size for at least one VM in the plurality of VMs based on the rECS values. The computer system can then adjust the number of cache blocks in the at least one VM's cache allocation based on the new cache allocation size.
摘要:
Systems and techniques are described for thread cache allocation. A described technique includes monitoring input and output accesses for a plurality of threads executing on a computing device that includes a cache comprising a quantity of memory blocks, determining a respective reuse intensity for each of the threads, determining a respective read ratio for each of the threads, determining a respective quantity of memory blocks for each of the partitions by optimizing a combination of cache utilities, each cache utility being based on the respective reuse intensity, the respective read ratio, and a respective hit ratio for a particular partition, and resizing one or more of the partitions to be equal to the respective quantity of the memory blocks for the partition.
摘要:
Techniques for achieving crash consistency when performing write-behind caching using a flash storage-based cache are provided. In one embodiment, a computer system receives from a virtual machine a write request that includes data to be written to a virtual disk and caches the data in a flash storage-based cache. The computer system further logs a transaction entry for the write request in the flash storage-based cache, where the transaction entry includes information usable for flushing the data from the flash storage-based cache to a storage device storing the virtual disk. The computer system then communicates an acknowledgment to the VM indicating that the write request has been successfully processed.
摘要:
Techniques for achieving crash consistency when performing write-behind caching using a flash storage-based cache are provided. In one embodiment, a computer system receives from a virtual machine a write request that includes data to be written to a virtual disk and caches the data in a flash storage-based cache. The computer system further logs a transaction entry for the write request in the flash storage-based cache, where the transaction entry includes information usable for flushing the data from the flash storage-based cache to a storage device storing the virtual disk. The computer system then communicates an acknowledgment to the VM indicating that the write request has been successfully processed.
摘要:
Techniques for automatically allocating space in a flash storage-based cache are provided. In one embodiment, a computer system collects I/O trace logs for a plurality of virtual machines or a plurality of virtual disks and determines cache utility models for the plurality of virtual machines or the plurality of virtual disks based on the I/O trace logs. The cache utility model for each virtual machine or each virtual disk defines an expected utility of allocating space in the flash storage-based cache to the virtual machine or the virtual disk over a range of different cache allocation sizes. The computer system then calculates target cache allocation sizes for the plurality of virtual machines or the plurality of virtual disks based on the cache utility models and allocates space in the flash storage-based cache based on the target cache allocation sizes.