IBM General Parallel File System for AIX: Administration and Programming Reference
Name
mmrpldisk - Replaces the specified disk.
Synopsis
mmrpldisk Device DiskName {DiskDesc | -F
DescFile} [-v yes | no]
[-N { all | mount |
NodeName[,NodeName ... ] }
]
Description
Use the mmrpldisk command to replace an existing disk in the GPFS
file system with a new one. All data on the old disk is migrated to the
new one.
Notes:
- You cannot replace a disk when it is the only remaining disk in the file
system.
- Under no circumstances should you replace a stopped disk. You need
to start a stopped disk before replacing it. If a disk cannot be
started, you must delete it using the -p option on the mmdeldisk command. See the IBM General Parallel File System for AIX: Problem
Determination Guide and search for disk media failures for
further information on handling this.
- When using Fibre Channel disks, single-node quorum is not
supported.
- The file system need not be unmounted before the mmrpldisk
command can be run.
Upon successful execution of the mmrpldisk command, the disk is
replaced in the file system and data is copied to the new disk without
restriping.
Parameters
- Device
- The device name of the file system where the disk is to be
replaced. File system names need not be fully qualified.
fs0 is as acceptable as /dev/fs0.
This must be the first parameter.
- Disk Name
- The name of the disk to be replaced which was previously passed to the mmcrfs, mmadddisk,
or mmrpldisk commands. You can have the
entire list of disk names displayed using the mmlsdisk command.
- DiskDesc
- A descriptor for the replacement disk.
Any parameter that is intentionally omitted or allowed to default must be
explicitly skipped. Trailing delimiters are acceptable.
- -F DescFile
- Specifies a file containing the disk descriptor for the replacement
disk.
Disk descriptors
The disk descriptor must be specified in the form:
DiskName:::DiskUsage:FailureGroup
- DiskName
- In an SP environment, you must specify the virtual shared disk
name. For details on generating a virtual shared disk, see Specifying disk descriptors and the mmcrvsd
command. To use an existing virtual shared disk in the file system,
only the virtual shared disk name need be specified in the disk
descriptor. GPFS performance and recovery processes function best with
one disk per virtual shared disk. If you want to create virtual shared
disks with more than one disk, refer to the IBM Parallel System Support Programs for
AIX: Managing Shared Disks manual.
In an HACMP environment, you must specify the logical volume
name. For details on generating a logical volume, see Specifying disk descriptors and the mmcrlv
command. To use an existing logical volume group in the file system,
only the logical volume name need be specified in the disk descriptor.
The disk name must be set up the same on all of the nodes in the
nodeset.
Logical volume use in an HACMP environment:
- Any disk resources (volume groups and logical volumes) that will be used
by GPFS must not belong to any HACMP/ES resource group. HACMP/ES will
not be in control of these disk resources and is not responsible for varying
them on or off at any time. The responsibility to keep the disks in the
proper state belongs to GPFS in the HACMP environment. For further
information on logical volume concepts, see the AIX System Management Guide:
Operating System and Devices.
- When using single-node quorum Fibre Channel attached disks are not
supported.
- Disk Usage
- Specify a disk usage or inherit the disk usage of the disk being
replaced:
- dataAndMetadata
- dataOnly
- metadataOnly
- Failure Group
- A number identifying the failure group to which this disk belongs.
You can specify any value from -1 (where -1 indicates that the disk has no
point of failure in common with any other disk) to 4000. If you do not
specify a failure group, the new disk inherits the failure group of the disk
being replaced.
- Note:
- While it is not absolutely necessary to specify the same disk descriptor
parameters for the new disk as the old disk, it is suggested you do so.
If the new disk is equivalent in size as the old disk, and if the
DiskUsage and FailureGroup parameters are the same, the data
and metadata can be completely migrated from the old disk to the new
disk. A disk replacement in this manner allows the file system to
maintain its current data and metadata balance.
If the new disk has a different size, DiskUsage parameter, or
FailureGroup parameter, the operation may leave the file system
unbalanced and require a restripe. Additionally, a change in size or
the DiskUsage parameter may cause the operation to fail since other
disks in the file system may not have sufficient space to absorb more data or
metadata. In this case you must first use mmadddisk to add the new disk, mmdeldisk to delete the old disk, and finally mmrestripefs to rebalance the file system.
- -N {all | mount |
NodeName[,NodeName ... ] }
- Specify the nodes which should participate in the migration of data from
the old to the new disk. Valid values are:
- all
- Indicates that all nodes in the GPFS nodeset, whether or not they have the
file system mounted, should participate in the migration. This is the
default when the -N option has not been specified.
- mount
- Indicates that only the nodes which have the file system mounted should
participate in the migration.
- NodeName[,NodeName ... ]
- A comma-separated list of nodes that should participate in the
migration.
The hostname or IP address used for a node must refer to the adapter port
over which the GPFS daemons communicate. Alias interfaces are not
allowed. Use the original address or a name that is resolved by the
host command to that original address. You may specify a node
using any of these forms:
| Format
| Example
|
| Short hostname
| k145n01
|
| Long hostname
| k145n01.kgn.ibm.com
|
| IP address
| 9.119.19.102
|
Options
- -v {yes | no}
- Verify that the new virtual shared disk does not belong to an existing
file system. The default is yes. Specify no
only when you want to reuse a disk that is no longer needed for an existing
file system.
Exit status
- 0
- Successful completion.
- 1
- A failure has occurred.
Security
You must have root authority to run the mmrpldisk command.
In an SP environment:
- Verify the authentication method set for SP security services:
- If your authentication method is set to compatibility, Kerberos
authentication is required. Issue the k4init command.
- If your authentication method is set to DCE, dce_login
authentication is required.
- If your authentication method is set to NONE/std, there must be an entry
in the /etc/sysctl.mmcmd.acl file on every node in
the nodeset for the root user at every other node in the nodeset.
For further information, see the latest IBM Parallel System
Support Programs for AIX: Administration Guide, IBM Parallel
System Support Programs for AIX: Command and Technical Reference,
and RS/6000: Planning Volume 2, Control Workstation and Software
Environment manuals at www.rs6000.ibm.com/resource/aix_resource/sp_books/pssp.
Search for information on sysctl.
- You may issue the mmrpldisk command from any node running GPFS or
the CWS.
- If you are executing the mmrpldisk command from the CWS on a
multi-partitioned system, the SP_NAME environment variable must be
properly set. It is suggested that you use a separate window for each
partition and set the environment variable accordingly. For further
information, see the IBM Parallel
System Support Programs for AIX: Administration Guide and
search for understanding system partitioning.
In an HACMP environment:
- When using rcp and rsh for remote communication, a
properly configured /.rhosts file must exist in the root
user's home directory on each node in the GPFS cluster. If you
have designated the use of a different remote communication program on either
the mmcrcluster or the mmchcluster command, you must insure:
- Proper authorization is granted to all nodes in the GPFS cluster.
- The nodes in the GPFS cluster can communicate without the use of a
password.
- You may issue the mmrpldisk command from any node in the GPFS
cluster.
Examples
To replace disk gpfs3n12 in fs3 with a new disk,
gpfs4n12 allowing the disk usage and failure group parameters to
default to the corresponding values of gpfs3n12, and have only
nodes k145n01, k145n03, and k145n05 participate in the restripe of the file
system, enter:
mmrpldisk fs3 gpfs3n12 gpfs4n12:::: -N k145n01,k145n03,k145n05
The system displays information similar to:
Replacing ...
GPFS: 6027-531 The following disks of fs3 will be formatted on node k145n03:
gpfs4n12: size 4390912 KB
Extending Allocation Map
GPFS: 6027-1503 Completed adding disks to file system fs3.
GPFS: 6027-589 Scanning file system metadata, phase 1 ...
77 % complete on Wed Jul 12 17:33:58 2000
100 % complete on Wed Jul 12 17:33:59 2000
GPFS: 6027-552 Scan completed successfully.
GPFS: 6027-589 Scanning file system metadata, phase 2 ...
GPFS: 6027-552 Scan completed successfully.
GPFS: 6027-589 Scanning file system metadata, phase 3 ...
GPFS: 6027-552 Scan completed successfully.
GPFS: 6027-565 Scanning user file metadata ...
1 % complete on Wed Jul 12 17:34:12 2000
100 % complete on Wed Jul 12 17:34:15 2000
GPFS: 6027-552 Scan completed successfully.
Done
mmrpldisk: 6027-1371 Propagating the changes to all affected nodes.
This is an asynchronous process.
See also
mmadddisk Command
mmchdisk Command
mmlsdisk Command
mmrestripefs Command
Location
/usr/lpp/mmfs/bin
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