NAME

mdtest - test file system metadata performance

SYNOPSIS

mdtest [-options]

DESCRIPTION

mdtest is a file system metadata performance test designed to run in a cluster MPI environment against parallel file systems.

In each iteration of the test, each MPI task creates, stats, and removes the specified number of directories and/or files and measures the performance in ops/second. After all the iterations complete, the maximum, minimum, mean ops/sec and the std. deviation are reported for each operation.

OPTIONS

-b branching_factor: The branching factor of the hierarchical directory structure [default: 1].
-B: No barriers will be taken between the phases (create/stat/remove) of the tests.
-c: Use ``collective creates'', meaning task 0 does all the creates.
-C: Only perform the create phase of the tests.
-d testdir[@testdir2]: The directory in which the tests will run. For multiple paths, must use fully-qualified pathnames. [default: working directory of mdtest].
-D: Perform test on directories only (no files).
-e bytes: Set the number of Bytes to read from each file [default: 0].
-E: Only perform the read phase of the tests.
-f first: The first number of tasks on which the test will run [default: 0].
-F: Perform test on files only (no directories).
-g: Use global default directory layout for test subdirectories (deletes inherited striping layout - Lustre only).
-h: Display help message.
-i iterations: The number of iterations the test will run [default: 1].
-I items_per_directory: The number of items per directory in the tree [default: 0].
-l last: The last number of tasks on which the test will run [default: 0].
-L: Files/directories only created at the leaf level of the tree.
-n number_of_items: Every process will creat/stat/remove # directories and files [default: 0].
-N stride: Stride # between neighbor tasks for file/dir stat, 0 = local [default: 0].
-p seconds: Pre-iteration delay (in seconds).
-P: Print both the file creation rate and the elapsed time.
-r: Only perform the remove phase of the tests.
-R[seed]: Randomly stat files. There is an optional argument that provides a seed to the random number generator. (Note: There is no space between the -R
and the seed if one is provided.)
-s stride: Stride between the number of tasks for each test [default: 1].
-S: Shared file access (file only, no directories).
-t: Include unique working directory management overhead in the results (presumes -u option).
-T: Only perform the stat phase of the tests.
-u: Create a unique working directory for each task (presumes -d option).
-v: Increase verbosity (each instance of option increments by one).
-V value: Set verbosity value [default: 0].
-w bytes: Set the number of Bytes to write to each file after it is created [default: 0].
-W seconds: Specify the stonewall time in seconds. When the stonewall timer has elapsed, the rank with the highest number of creates sets number_of_items for the other ranks, so that all ranks create the same number of files.
-x filename: Filename to use for stonewall synchronization between processes.
Y: Call the sync command after each phase, which is included in the timing. Note that it causes all IO to be flushed from the nodes.
-z tree_depth: The depth of the hierarchical directory tree [default: 0].

EXAMPLES

Example 1

$ mpirun -n 2 ./mdtest -d /tmp/z -n 100 -i 2
-- started at 11/23/2009 09:05:29 --
mdtest-1.8.1 was launched with 2 total task(s) on 1 nodes
Command line used: ./mdtest -d /tmp/z -n 100 -i 2
Path: /tmp
FS: 28.8 GiB   Used FS: 8.6%   8.6%Inodes: 1.8 Mi   Used Inodes: 5.1%
time to create tree: 0.000078 sec
tree creation rate: 12826.617737 ops/sec
2 tasks, 200 files/directories
SUMMARY: (of 2 iterations)


   Operation                  Max        Min       Mean    Std Dev


   ---------                  ---        ---       ----    -------


   Directory creation:  21489.415  17447.551  19468.483   2020.932


   Directory stat    : 154657.227  28731.061  91694.144  62963.083


   Directory removal : 146756.613  21489.415  84123.014  62633.599


   File creation     :  42024.989  28731.061  35378.025   6646.964


   File stat         : 146756.613  17447.551  82102.082  64654.531


   File removal      : 156884.384  42024.989  99454.686  57429.698


                        
time to remove tree: 0.001031 sec
tree removal rate: 970.005550 ops/sec
-- finished at 11/23/2009 09:05:29 --

Example 2

$ mpirun -np 2 -H pc6 ./mdtest -d /tmp/z -b 2 -z 3 -I 10
-- started at 11/23/2009 09:09:23 --
mdtest-1.8.1 was launched with 2 total task(s) on 1 nodes
Command line used: ./mdtest -d /tmp/z -b 2 -z 3 -I 10
Path: /tmp
FS: 28.8 GiB   Used FS: 8.6%   8.6%Inodes: 1.8 Mi   Used Inodes: 5.1%
time to create tree: 0.000765 sec
tree creation rate: 19605.659084 ops/sec
2 tasks, 300 files/directories
SUMMARY: (of 1 iterations)


   Operation                  Max        Min       Mean    Std Dev


   ---------                  ---        ---       ----    -------


   Directory creation:  29365.707  29365.707  29365.707      0.000


   Directory stat    : 123701.455 123701.455 123701.455      0.000


   Directory removal :  25623.459  25623.459  25623.459      0.000


   File creation     :  38704.743  38704.743  38704.743      0.000


   File stat         : 125477.782 125477.782 125477.782      0.000


   File removal      :  51911.845  51911.845  51911.845      0.000
time to remove tree: 0.000940 sec
tree removal rate: 15960.060883 ops/sec
-- finished at 11/23/2009 09:09:23 --