mmlsdisk command

Displays the current configuration and state of the disks in a file system.

Synopsis

mmlsdisk Device [-d "DiskName[;DiskName...]"] [-e | -Y] [-L]

or

mmlsdisk Device [-d "DiskName[;DiskName...]"] {-m | -M} [-Y]

Availability

Available on all IBM Storage Scale editions.

Description

Use the mmlsdisk command to display the current state of the disks in the file system.

The mmlsdisk command may be run against a mounted or unmounted file system.

For each disk in the list, the mmlsdisk command displays the following:
  • Disk name
  • Driver type
  • Logical sector size (under the heading sector size)
  • Failure group
  • Whether it holds metadata
  • Whether it holds data
  • Status:
    ready
    Normal status.
    suspended
    or
    to be emptied
    Indicates that data is to be migrated off this disk.
    being emptied
    Transitional status in effect while a disk deletion is pending.
    emptied
    Indicates that data is already migrated off this disk.
    replacing
    Transitional status in effect for old disk while replacement is pending.
    replacement
    Transitional status in effect for new disk while replacement is pending.
  • Availability:
    up
    The disk is available to GPFS for normal read and write operations.
    down
    No read and write operations can be performed on this disk.
    recovering
    An intermediate state for disks coming up, during which GPFS verifies and corrects data. write operations can be performed while a disk is in this state, but read operations cannot (because data on the disk being recovered might be stale until the mmchdisk start command completes).
    unrecovered
    The disk was not successfully brought up.
  • Disk ID
  • Storage pool to which the disk is assigned
  • Remarks: A tag is displayed if the disk is a file system descriptor replica holder, an excluded disk, or the disk supports space reclaim.

Parameters

Device
The device name of the file system to which the disks belong. File system names need not be fully-qualified. fs0 is as acceptable as /dev/fs0.

This must be the first parameter.

-d "DiskName[;DiskName...]"
The name of the disks for which you want to display current configuration and state information. When you enter multiple values for DiskName, separate them with semicolons and enclose the list in quotation marks. 
"gpfs3nsd;gpfs4nsd;gpfs5nsd"

Options

-e
Displays all of the disks in the file system that do not have an availability of up and a status of ready. If all disks in the file system are up and ready, the message displayed is: 
6027-623 All disks up and ready
-L
Displays an extended list of disk parameters that includes the disk id column and the remarks column. The remarks column can contain one or more of the following tags:
desc
The disk is a file system descriptor replica holder.
excl
The disk is excluded by the mmfsctl command.
{nvme(t) | scsi(t) | auto(t)}
The disk is a device support space reclaim:
nvme(t)
The disk is a TRIM capable NVMe device that supports the mmreclaimspace command.
scsi(t)
The disk is a thin provisioned SCSI disk that supports the mmreclaimspace command.
auto(t)
The disk is either an nvme(t) device or a scsi(t) device. IBM Storage Scale will try to detect the actual disk type automatically. To avoid problems, you should replace auto with the correct disk type, nvme or scsi, as soon as you can.
Note: In 5.0.5, the space reclaim auto-detection is enhanced. It is encouraged to use the auto keyword after your cluster is upgraded to 5.0.5.
For more information, see IBM Storage Scale with data reduction storage devices.
-M
Displays whether I/O requests to the disk are satisfied on the local node, or using an NSD server. If the I/O is done using an NSD server, shows the NSD server name and the underlying disk name on that server node.
-m
Displays whether I/O requests to the disk are satisfied on the local node, or using an NSD server. The scope of this option is the node on which the mmlsdisk command is issued.
-Y
Displays the command output in a parseable format with a colon (:) as a field delimiter. Each column is described by a header.
Note: Fields that have a colon (:) are encoded to prevent confusion. For the set of characters that might be encoded, see the command documentation of mmclidecode. Use the mmclidecode command to decode the field.

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. For more information, see Requirements for administering a GPFS file system.

As root, the command can also do an mmlsdisk on remote file systems.

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 mmlsdisk command was issued.

The mmlsdisk command does not work if GPFS is down.

Examples

  1. To display the current state of gpfs2nsd, issue the following command: 
    # mmlsdisk /dev/fs0 -d gpfs2nsd
    A sample output is as follows:
    disk      driver  sector failure holds    holds                     storage
name      type      size   group metadata data  status  availability pool
--------  ------- ------ ------- -------- ----- ------- ------------ -------
gpfs2nsd  nsd        512    4002 yes      yes   ready   up           system
    Note: In this output, sector size refers to logical sector size.
  2. To display the current states of gpfs2nsd, gpfs3nsd, and gpfs4nsd, and display their respective disk ids and the descriptor quorum assignment, issue the following command: 
    # mmlsdisk /dev/fs0 -d "gpfs2nsd;gpfs3nsd;gpfs4nsd" -L
    A sample output is as follows:
    disk      driver sector failure holds    holds                             storage
name      type     size   group metadata data  status availability disk id pool     remarks
--------- ------ ------ ------- -------- ----- ------ ------------ ------- -------- -------
gpfs2nsd  nsd      512    4002  yes      yes   ready  up           2       system    desc
gpfs3nsd  nsd      512    4002  yes      yes   ready  up           3       system
gpfs4nsd  nsd      512    4002  yes      yes   ready  up           4       system
Number of quorum disks: 3
Read quorum value:      2
Write quorum value:     2
    Note: In this output, sector size refers to logical sector size.
  3. After the mmchdisk fs0 empty -d gpfs1nsd command has been issued, you can view the current state of gpfs1nsd by issuing the following command:
    # mmlsdisk fs0 -L
    A sample output from IBM Storage Scale 4.1.1 and later is as follows:
    disk     driver sector failure holds   holds                                  storage
name     type   size   group  metadata data  status     availability  disk id pool  
-------- ------ ------ ------ -----    ----- -----      ------------- ------- ----- 
gpfs1nsd nsd     512      -1  Yes      Yes   to be emptied up              1  system
gpfs2nsd nsd     512      -1  Yes      Yes   to be emptied up              2  system
gpfs3nsd nsd     512      -1  Yes      Yes   ready         up              3  system
gpfs4nsd nsd     512      -1  Yes      Yes   ready         up              4  system
Number of quorum disks: 3
Read quorum value:      2
Write quorum value:     2
Attention: Due to an earlier configuration change the file system
may contain data that is at risk of being lost.
  4. To display whether the I/O is performed locally or using an NSD server, the NSD server name, and the underlying disk name for the file system named test, issue the following command: 
    # mmlsdisk test -M
    A sample output is as follows:
    Disk name     IO performed on node     Device             Availability
------------  -----------------------  -----------------  ------------
gpfs7nsd      localhost                /dev/hdisk12       up
gpfs10nsd     k5n88.kgn.ibm.com        /dev/hdisk13       up
gpfs4nsd      localhost                /dev/hdisk10       up
  5. To display the same information as in the previous example, but limited to the node on which the command is issued, issue the following command: 
    # mmlsdisk test -m
    A sample output is as follows:
    Disk name     IO performed on node     Device             Availability
------------  -----------------------  -----------------  ------------
gpfs7nsd      localhost                /dev/hdisk12       up
gpfs10nsd     k5n88.kgn.ibm.com             -             up
gpfs4nsd      localhost                /dev/hdisk10       up

See also

Location

/usr/lpp/mmfs/bin