Name
Abstract | ||
|---|---|---|
Solid state disks (SSDs) have advanced to outperform traditional hard drives significantly in both random reads and writes. However, heavy random writes trigger fre- quent garbage collection and decrease the performance of SSDs. In an SSD array, garbage collection of individ- ual SSDs is not synchronized, leading to underutilization of some of the SSDs. We propose a software solution to tackle the unsyn- chronized garbage collection in an SSD array installed in a host bus adaptor (HBA), where individual SSDs are exposed to an operating system. We maintain a long I/O queue for each SSD and flush dirty pages intelligently to fill the long I/O queues so that we hide the performance imbalance among SSDs even when there are few parallel application writes. We further define a policy of select- ing dirty pages to flush and a policy of taking out stale flush requests to reduce the amount of data written to SSDs. We evaluate our solution in a real system. Experi- ments show that our solution fully utilizes all SSDs in an array under random write-heavy workloads. It improves I/O throughput by up to 62% under random workloads of mixed reads and writes when SSDs are under active garbage collection. It causes little extra data writeback and increases the cache hit rate. |
Year | Venue | Field |
|---|---|---|
2015 | CoRR | Cache hit rate,Computer science,Parallel computing,Queue,Real-time computing,Software,Garbage collection,Throughput,Solid-state,Operating system |
DocType | Volume | Citations |
Journal | abs/1506.07566 | 1 |
PageRank | References | Authors |
0.35 | 8 | 3 |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Da Zheng | 1 | 95 | 8.61 |
| Randal Burns | 2 | 1955 | 115.15 |
| Alexander S. Szalay | 3 | 959 | 105.36 |