Ceph 包含 rados bench 命令，用于对 RADOS 存储集群执行性能基准测试。命令将执行写入测试和两种类型的读取测试。在测试读写性能时使用 --no-cleanup 选项。默认情况下，rados bench 命令将删除它写入存储池中的对象。离开这些对象后，有两个读取测试可以测量顺序和随机读取性能。
注意
在运行这些性能测试前，运行以下命令丢弃所有文件系统缓存：
# echo 3 | sudo tee /proc/sys/vm/drop_caches && sudo sync
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创建新存储池：
# ceph osd pool create testbench 100 100
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对新创建的存储池执行 10 秒写入测试：
# rados bench -p testbench 10 write --no-cleanup
输出示例
ExpandMaintaining 16 concurrent writes of 4194304 bytes for up to 10 seconds or 0 objects Object prefix: benchmark_data_cephn1.home.network_10510 sec Cur ops started finished avg MB/s cur MB/s last lat avg lat 0 0 0 0 0 0 - 0 1 16 16 0 0 0 - 0 2 16 16 0 0 0 - 0 3 16 16 0 0 0 - 0 4 16 17 1 0.998879 1 3.19824 3.19824 5 16 18 2 1.59849 4 4.56163 3.87993 6 16 18 2 1.33222 0 - 3.87993 7 16 19 3 1.71239 2 6.90712 4.889 8 16 25 9 4.49551 24 7.75362 6.71216 9 16 25 9 3.99636 0 - 6.71216 10 16 27 11 4.39632 4 9.65085 7.18999 11 16 27 11 3.99685 0 - 7.18999 12 16 27 11 3.66397 0 - 7.18999 13 16 28 12 3.68975 1.33333 12.8124 7.65853 14 16 28 12 3.42617 0 - 7.65853 15 16 28 12 3.19785 0 - 7.65853 16 11 28 17 4.24726 6.66667 12.5302 9.27548 17 11 28 17 3.99751 0 - 9.27548 18 11 28 17 3.77546 0 - 9.27548 19 11 28 17 3.57683 0 - 9.27548 Total time run: 19.505620 Total writes made: 28 Write size: 4194304 Bandwidth (MB/sec): 5.742 Stddev Bandwidth: 5.4617 Max bandwidth (MB/sec): 24 Min bandwidth (MB/sec): 0 Average Latency: 10.4064 Stddev Latency: 3.80038 Max latency: 19.503 Min latency: 3.19824 -
对存储池执行 10 秒的后续读取测试：
# rados bench -p testbench 10 seq
输出示例
sec Cur ops started finished avg MB/s cur MB/s last lat avg lat 0 0 0 0 0 0 - 0 Total time run: 0.804869 Total reads made: 28 Read size: 4194304 Bandwidth (MB/sec): 139.153 Average Latency: 0.420841 Max latency: 0.706133 Min latency: 0.0816332
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对存储池执行 10 秒随机读取测试：
# rados bench -p testbench 10 rand
输出示例
sec Cur ops started finished avg MB/s cur MB/s last lat avg lat 0 0 0 0 0 0 - 0 1 16 46 30 119.801 120 0.440184 0.388125 2 16 81 65 129.408 140 0.577359 0.417461 3 16 120 104 138.175 156 0.597435 0.409318 4 15 157 142 141.485 152 0.683111 0.419964 5 16 206 190 151.553 192 0.310578 0.408343 6 16 253 237 157.608 188 0.0745175 0.387207 7 16 287 271 154.412 136 0.792774 0.39043 8 16 325 309 154.044 152 0.314254 0.39876 9 16 362 346 153.245 148 0.355576 0.406032 10 16 405 389 155.092 172 0.64734 0.398372 Total time run: 10.302229 Total reads made: 405 Read size: 4194304 Bandwidth (MB/sec): 157.248 Average Latency: 0.405976 Max latency: 1.00869 Min latency: 0.0378431
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要增加并发读写的数量，使用
-t选项，默认是 16 个线程。另外，-b参数可以调整要写入的对象的大小。默认对象大小为 4MB。安全的最大对象大小为 16MB。红帽建议在不同的池中运行这些基准测试的多个副本。这样做可显示多个客户端的性能变化。添加
--run-name <label>选项来控制在基准测试过程中写入的对象的名称。通过更改每个正在运行的命令实例的--run-name标签，可以同时运行多个rados bench命令。这可以防止多个客户端尝试访问同一对象并允许不同的客户端访问不同的对象时可能会出现 I/O 错误。--run-name选项在尝试模拟实际工作负载时也很有用。例如：# rados bench -p testbench 10 write -t 4 --run-name client1
输出示例
ExpandMaintaining 4 concurrent writes of 4194304 bytes for up to 10 seconds or 0 objects Object prefix: benchmark_data_node1_12631 sec Cur ops started finished avg MB/s cur MB/s last lat avg lat 0 0 0 0 0 0 - 0 1 4 4 0 0 0 - 0 2 4 6 2 3.99099 4 1.94755 1.93361 3 4 8 4 5.32498 8 2.978 2.44034 4 4 8 4 3.99504 0 - 2.44034 5 4 10 6 4.79504 4 2.92419 2.4629 6 3 10 7 4.64471 4 3.02498 2.5432 7 4 12 8 4.55287 4 3.12204 2.61555 8 4 14 10 4.9821 8 2.55901 2.68396 9 4 16 12 5.31621 8 2.68769 2.68081 10 4 17 13 5.18488 4 2.11937 2.63763 11 4 17 13 4.71431 0 - 2.63763 12 4 18 14 4.65486 2 2.4836 2.62662 13 4 18 14 4.29757 0 - 2.62662 Total time run: 13.123548 Total writes made: 18 Write size: 4194304 Bandwidth (MB/sec): 5.486 Stddev Bandwidth: 3.0991 Max bandwidth (MB/sec): 8 Min bandwidth (MB/sec): 0 Average Latency: 2.91578 Stddev Latency: 0.956993 Max latency: 5.72685 Min latency: 1.91967 -
删除
rados bench命令创建的数据：# rados -p testbench cleanup