-b: branching factor of hierarchical directory structure 目录树的分支参数 -B: no barriers between phases (create/stat/remove) 不同的阶段没有隔离 (create/stat/remove)； -c: collective creates: task 0 does all creates and deletes 共同创建: task 0 完成所有的创建和删除工作； -C: only create files/dirs 只创建文件或目录，不作删除； -d: the directory inwhich the tests will run 指出测试运行的目录（若不指定，则默认当前目录）； -D: perform test on directories only (no files) 只对目录操作进行测试（不包括文件）； -e: number of bytes to read from each file 从每个文件读出的文件大小 -E: only read files 只读取文件 -f: first number of tasks on which the test will run 首先运行的任务号； -F: perform test on files only (no directories) 只创建文件，没有目录； -h: prints help message 输出帮助信息 -i: number of iterations the test will run 测试迭代循环次数； -I: number of items per tree node 每个树节点包含的项目 -l: last number of tasks on which the test will run 最后运行的任务号 -L: files/dirs created only at leaf level 只在目录树的“叶子”层创建文件/目录； -n: every task will create/stat/remove # files/dirs per tree 每个任务需要再每棵树中create/stat/remove的文件/目录数； -N: stride # between neighbor tasks for file/dir stat (local=0) 遍历时指定和相邻任务的跨度 -p: pre-iteration delay (in seconds) 每次迭代之间延时（以秒计算） -r: only remove files/dirs 删除文件/目录 -R: randomly stat files/dirs (optional seed can be provided) 随机遍历文件/目录 ； -s: stride between the number of tasks for each test 每次测试的任务数的跨度 -S: shared file access (file only, no directories) 共享文件访问（只针对文件操作）； -t: time unique working directory overhead 记录特定目录的时间开销 -T: only stat files/dirs -u: unique working directory for each task 为每个任务指定工作目录； -v: verbosity (each instance of option increments by one) -V: verbosity value -w: number of bytes to write to each file 写到每个文件的字节数 -y: sync file after write completion 再写执行完后同步文件到磁盘（同步写） -z: depth of hierarchical directory structure 目录树的深度；
NOTES: * -N allows a "read-your-neighbor" approach by setting stride to tasks-per-node. Do not use it with -B, as it creates race conditions. 允许"read-your-neighbor" 方法 * -d allows multiple paths for the form '-d fullpath1@fullpath2@fullpath3' 可以指定多个测试路径，'-d fullpath1@fullpath2@fullpath3' * -B allows each task to time itself. The aggregate results reflect this change. 允许每个任务对自己进行计时； * -n and -I cannot be used together. -I specifies the number of files/dirs created per tree node, whereas the -n specifies the total number of files/dirs created over an entire tree. When using -n, integer division is used to determine the number of files/dirs per tree node. (E.g. if -n is 10 and there are 4 tree nodes (z=1 and b=3), there will be 2 files/dirs per tree node.) * -R and -T can be used separately. -R merely indicates that if files/dirs are going to be stat'ed, then they will be stat'ed randomly. 不能同时使用，因为指定了每个树节点的文件/目录数量，而-I指定的是整棵树的文件/目录数量。
In this example, the tree has a depth of one (z=1) and branching factor of three (b=3). The node at the top of the tree is the root node. The level of nodes furthest from the root is the leaf level. All trees created by mdtest are balanced. 这个例子中，目录树深度为1（z=1）,每个节点分支为3（b=3）.最上面的节点为根节点，
mdtest-1.9.3 was launched with 2 total task(s) on 1 node(s) Command line used: mdtest -I 10 -z 5 -b 2 -d /mnt/zptest/ -t -c 2 Path: /mnt/zptest FS: 6.5 TiB Used FS: 59.2% Inodes: 0.6 Mi Used Inodes: 100.0%
2 tasks, 1260 files/directories
SUMMARY: (of 1 iterations) Operation Max Min Mean Std Dev --------- --- --- ---- ------- Directory creation: 312.088 312.088 312.088 0.000 Directory stat : 73447.245 73447.245 73447.245 0.000 Directory removal : 255.755 255.755 255.755 0.000 File creation : 638.824 638.824 638.824 0.000 File stat : 86747.366 86747.366 86747.366 0.000 File read : 84434.232 84434.232 84434.232 0.000 File removal : 207.545 207.545 207.545 0.000 Tree creation : 39.062 39.062 39.062 0.000 Tree removal : 46.971 46.971 46.971 0.000
mdtest-1.9.3 was launched with 2 total task(s) on 2 node(s) Command line used: mdtest -I 10 -z 5 -b 2 -d /mnt/zptest/ -t -c 2 Path: /mnt/zptest FS: 6.5 TiB Used FS: 59.2% Inodes: 0.6 Mi Used Inodes: 100.0%
2 tasks, 1260 files/directories
SUMMARY: (of 1 iterations) Operation Max Min Mean Std Dev --------- --- --- ---- ------- Directory creation: 312.355 312.355 312.355 0.000 Directory stat : 1611.000 1611.000 1611.000 0.000 Directory removal : 127.333 127.333 127.333 0.000 File creation : 309.295 309.295 309.295 0.000 File stat : 113257.534 113257.534 113257.534 0.000 File read : 203458.057 203458.057 203458.057 0.000 File removal : 98.523 98.523 98.523 0.000 Tree creation : 36.566 36.566 36.566 0.000 Tree removal : 20.191 20.191 20.191 0.000
-- finished at 01/27/2015 21:05:12 --
关于目录生成的问题： 这个是 -z 2 -b 3
1 2 3 4
[root@lab8106 mnt]# ls mdtest2/#test-dir.0/mdtest_tree.0/ mdtest_tree.1 mdtest_tree.2 mdtest_tree.3 [root@lab8106 mnt]# ls mdtest2/#test-dir.0/mdtest_tree.0/mdtest_tree.1/ mdtest_tree.4 mdtest_tree.5 mdtest_tree.6
这个是以这个目录开始的
1
[root@lab8106 mnt]# ls mdtest2/#test-dir.0/mdtest_tree.0/
