我注意到我的备份非常慢，所以我使用 sysbench 进行了速度测试，如下所示：
$ mkdir benchmark
$ cd benchmark
$ sysbench fileio prepare
$ sysbench fileio --file-test-mode=rndrw run
结果如下：
sysbench 1.0.11 (using system LuaJIT 2.1.0-beta3)
Running the test with following options:
Number of threads: 1
Initializing random number generator from current time
Extra file open flags: 0
128 files, 16MiB each
2GiB total file size
Block size 16KiB
Number of IO requests: 0
Read/Write ratio for combined random IO test: 1.50
Periodic FSYNC enabled, calling fsync() each 100 requests.
Calling …