mmdf command

Queries available file space on a GPFS™ file system.

Synopsis

mmdf Device [-d] [-F] [-m] [-P PoolName] [--block-size {BlockSize | auto}]

Availability

Available on all GPFS editions.

Description

Use the mmdf command to display available file space on a GPFS file system. For each disk in the GPFS file system, the mmdf command displays this information, by failure group and storage pool:
  • The size of the disk.
  • The failure group of the disk.
  • Whether the disk is used to hold data, metadata, or both.
  • Available space in full blocks.
  • Available space in fragments.

Displayed values are rounded down to a multiple of 1024 bytes. If the fragment size used by the file system is not a multiple of 1024 bytes, then the displayed values may be lower than the actual values. This can result in the display of a total value that exceeds the sum of the rounded values displayed for individual disks. The individual values are accurate if the fragment size is a multiple of 1024 bytes.

For the file system, the mmdf command displays the total number of inodes and the number available.

The mmdf command may be run against a mounted or unmounted file system.
Notes:
  1. This command is I/O intensive and should be run when the system load is light.
  2. An asterisk at the end of a line means that this disk is in a state where it is not available for new block allocation.

Parameters

Device
The device name of the file system to be queried for available file space. File system names need not be fully-qualified. fs0 is as acceptable as /dev/fs0.

This must be the first parameter.

-d
List only disks that can hold data.
-F
List the number of inodes and how many of them are free.
-m
List only disks that can hold metadata.
-P PoolName
Lists only disks that belong to the requested storage pool.
--block-size {BlockSize | auto}
Specifies the unit in which the number of blocks is displayed. The value must be of the form [n]K, [n]M, [n]G or [n]T, where n is an optional integer in the range 1 to 1023. The default is 1K. If auto is specified, the number of blocks is automatically scaled to an easy-to-read value.

Exit status

0
Successful completion.
nonzero
A failure has occurred.

Security

If you are a root user, the node on which the command is issued must be able to execute remote shell commands on any other node in the cluster without the use of a password and without producing any extraneous messages. See the following GPFS: Administration and Programming Reference topic: Requirements for administering a GPFS file system.

If you are a non-root user, you may specify only file systems that belong to the same cluster as the node on which the mmdf command was issued.

Examples

  1. To query all disks in the fs2 file system that can hold data, issue this command: 
    mmdf fs2 -d
    The system displays information similar to: 
    disk        disk size  failure holds    holds  free KB in  free KB in
name            in KB    group metadata data  full blocks  fragments
----------- --------- -------- -------- ----  -----------  ---------
Disks in storage pool: system (Maximum disk size allowed is 833 GB)
         -------------                           -------- ----------
(pool total)        0                            0 (0%)      0 (0%)

Disks in storage pool: sp1 (Maximum disk size allowed is 359 GB)
gpfs1002nsd   8897968        1 no       yes  8342016 (94%)    928 (0%)
            ---------                       ------------- ------------
(pool total)  8897968                        8342016 (94%)    928 (0%)

            =========                       ============== ============
(data)        8897968                        8342016 (94%)    928 (0%)
(metadata)          0                              0 (0%)       0 (0%)
            =========                       ============= ============
(total)       8897968                        8342016 (94%)    928 (0%)
  2. To query all disks in the fs1 file system with the number of blocks automatically scaled to an easy-to-read value, issue this command: 
     mmdf fs1 --block-size auto
    The system displays information similar to: 
    disk                disk size  failure holds    holds                 free                free
name                             group metadata data        in full blocks        in fragments
--------------- ------------- -------- -------- ----- -------------------- -------------------
Disks in storage pool: system (Maximum disk size allowed is 437 GB)
gpfs1001nsd             33.4G        1 yes      no           33.19G ( 99%)          2.5M ( 0%)
gpfs1002nsd             33.4G        1 yes      no            33.2G ( 99%)          2.5M ( 0%)
gpfs1003nsd             33.4G        2 yes      no            33.2G ( 99%)          2.5M ( 0%)
gpfs1004nsd             33.4G        2 yes      no           33.27G (100%)          2.5M ( 0%)
gpfs1005nsd             33.4G        2 yes      no           33.32G (100%)        1.562M ( 0%)
                -------------                         -------------------- -------------------
(pool total)             167G                                166.2G (100%)        11.56M ( 0%)

Disks in storage pool: sp1 (Maximum disk size allowed is 484 GB)
gpfs1006nsd             33.4G        4 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1007nsd             33.4G        4 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1008nsd             33.4G        4 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1010nsd             33.4G        4 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1011nsd             33.4G        4 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1012nsd             33.4G        5 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1013nsd             33.4G        5 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1014nsd             33.4G        5 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1015nsd             33.4G        5 no       yes           33.4G (100%)        1.562M ( 0%)
gpfs1016nsd             33.4G        5 no       yes           33.4G (100%)        1.562M ( 0%)
                -------------                         -------------------- -------------------
(pool total)             334G                                  334G (100%)        15.62M ( 0%)

                =============                         ==================== ===================
(data)                   334G                                  334G (100%)        15.62M ( 0%)
(metadata)               167G                                166.2G (100%)        11.56M ( 0%)
                =============                         ==================== ===================
(total)                  501G                                500.2G (100%)        27.19M ( 0%)

Inode Information
-----------------
Number of used inodes:            4043
Number of free inodes:          497717
Number of allocated inodes:     501760
Maximum number of inodes:       514048
  3. To query fs1 for inode information, issue this command: 
    mmdf fs1 -F
    The system displays information similar to: 
    Inode Information
-----------------
Number of used inodes:            4043
Number of free inodes:          497717
Number of allocated inodes:     501760
Maximum number of inodes:       514048

See also

See also the following GPFS: Administration and Programming Reference topics:

Location

/usr/lpp/mmfs/bin
Parent topic: GPFS commands