source: gpfs_3.1_ker2.6.20/share/man/man8/mmadddisk.8 @ 51

.TH mmadddisk 02/16/06

mmadddisk Command

.SH "Name"

.PP

\fBmmadddisk\fR - Adds disks to a GPFS file system.

.SH "Synopsis"

.PP

\fBmmadddisk\fR \fIDevice\fR

{"\fIDiskDesc\fR[;\fIDiskDesc\fR...]"

| \fB-F\fR \fIDescFile\fR} [\fB-a\fR]

[\fB-r\fR] [\fB-v\fR {\fB\fIyes\fR\fR |

\fBno\fR}] [\fB-N\fR

{\fINode\fR[,\fINode\fR...] |

\fINodeFile\fR | \fINodeClass\fR}]

.SH "Description"

.PP

Use the \fBmmadddisk\fR command to add disks to a GPFS file

system. This command optionally rebalances an existing file system

after adding disks when the \fB-r\fR flag is specified. The

\fBmmadddisk\fR command does not require the file system to be unmounted

before issuing the command. The file system can be in use while the

command is run.

.PP

\fIDevice\fR must be the first parameter.

.PP

The \fB-N\fR parameter can be used only in conjunction with the

\fB-r\fR option.

.PP

To add disks to a GPFS file system, you first must decide if you will:

.RS +3

.HP 3

1. Create new disks using the

\fBmmcrnsd\fR

command. 

.sp

You should also decide whether to use the rewritten disk descriptor file

produced by the

\fBmmcrnsd\fR command, or create a

new list of disk descriptors. When using the rewritten file, the

\fIDisk Usage\fR and \fIFailure Group\fR specifications will remain the

same as specified on the

\fBmmcrnsd\fR

command.

.HP 3

2. Select disks no longer in use in any file system. Issue the \fBmmlsnsd -F\fR command to display the available

disks.

.RE

.SH "Parameters"

.PP

.RS +3

\fB\fIDevice\fR

\fR

.RE

.RS +9

The device name of the file system to which the disks are added.

File system names need not be fully-qualified. \fBfs0\fR is as

acceptable as \fB/dev/fs0\fR.

.PP

This must be the first parameter.

.RE

.PP

.RS +3

\fB\fIDiskDesc\fR

\fR

.RE

.RS +9

A descriptor for each disk to be added. Each descriptor is

delimited by a semicolon (;) and the entire list must be enclosed in

quotation marks (' or "). 

.PP

The current maximum number of disk descriptors that can be defined

for any single file system is 268 million. 

However, to achieve this maximum limit, you must recompile GPFS.

The actual number of disks in your file system may be 

constrained by products other than GPFS that you have

installed. Refer to the individual product documentation.

.PP

A disk descriptor is defined as (second, third and sixth fields

reserved):

.sp

.nf

DiskName:::DiskUsage:FailureGroup::StoragePool:

.fi

.sp

.PP

.RS +3

\fB\fIDiskName\fR

\fR

.RE

.RS +9

.PP

You must specify the name of the NSD previously created by the \fBmmcrnsd\fR command. For a list of available

disks, issue the

\fBmmlsnsd -F\fR command.

.RE

.PP

.RS +3

\fB\fIDiskUsage\fR

\fR

.RE

.RS +9

Specify a disk usage or accept the default: 

.PP

.RS +3

\fBdataAndMetadata

\fR

.RE

.RS +9

Indicates that the disk contains both data and metadata. This is

the default.

.RE

.PP

.RS +3

\fBdataOnly

\fR

.RE

.RS +9

Indicates that the disk contains data and does not contain

metadata.

.RE

.PP

.RS +3

\fBmetadataOnly

\fR

.RE

.RS +9

Indicates that the disk contains metadata and does not contain

data.

.RE

.PP

.RS +3

\fBdescOnly

\fR

.RE

.RS +9

Indicates that the disk contains no data and no file metadata. Such

a disk is used solely to keep a copy of the file system descriptor, and can be

used as a third failure group in certain disaster recovery

configurations. For more information, see

\fIGeneral Parallel File System: Advanced

Administration\fR and search on \fISynchronous mirroring utilizing

GPFS replication\fR.

.RE

.RE

.PP

.RS +3

\fB\fIFailureGroup\fR

\fR

.RE

.RS +9

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 value defaults to the NSD primary server node

number plus 4000. If an NSD server node is not specified, the value

defaults to -1. GPFS uses this information during data and metadata

placement to assure that no two replicas of the same block are written in such

a way as to become unavailable due to a single failure. All disks that

are attached to the same NSD server or adapter should be placed in the same

failure group.

.PP

If replication of \fB-m\fR or \fB-r\fR is set to

2 for the file system, storage pools must have two failure groups for the

commands to work properly.

.RE

.PP

.RS +3

\fB\fIStoragePool\fR

\fR

.RE

.RS +9

Specifies the storage pool to which the disk is to be assigned. If

this name is not provided, the default is \fBsystem\fR.

.PP

Only the \fBsystem\fR pool may contain \fBmetadataOnly\fR,

\fBdataAndMetadata\fR, or \fBdescOnly\fR disks.

.RE

.RE

.PP

.RS +3

\fB-F \fIDescFile\fR

\fR

.RE

.RS +9

Specifies a file containing a list of disk descriptors, one per

line. You may use the rewritten \fIDiskDesc\fR file created by the

\fBmmcrnsd\fR command or create your own file.

When using the \fIDiskDesc\fR file created by the \fBmmcrnsd\fR command, the values supplied on input to

the command for \fIDisk Usage\fR and \fIFailureGroup \fR are

used. When creating your own file, you must specify these values or

accept the system defaults. A sample file can be found in

\fB/usr/lpp/mmfs/samples/diskdesc\fR.

.RE

.PP

.RS +3

\fB-N { \fINode\fR[,\fINode\fR...]

| \fINodeFile\fR | \fINodeClass\fR}

\fR

.RE

.RS +9

Specifies the nodes that are to participate in the restripe of the file

system after the specified disks have been made available for use by

GPFS. This parameter can be used only in conjunction with the \fB-r

\fR option. This command supports all defined node classes.

The default is \fBall\fR (all nodes in the GPFS cluster will participate in

the restripe of the file system).

.PP

For information on how to specify node names, see \fISpecifying nodes as input to GPFS commands\fR

in \fIGPFS: Administration and Programming Reference\fR.

.RE

.SH "Options"

.PP

.RS +3

\fB-a

\fR

.RE

.RS +9

Specifies asynchronous processing. If this flag is specified, the

\fBmmadddisk\fR command returns after the file system descriptor is updated

and the rebalancing scan is started; it does not wait for rebalancing to

finish. If no rebalancing is requested (the \fB-r\fR flag not

specified), this option has no effect.

.RE

.PP

.RS +3

\fB-r

\fR

.RE

.RS +9

Rebalance all existing files in the file system to make use of new

disks.

.RS +3

\fBNote:\fR

.RE

.RS +9

Rebalancing of files is an I/O intensive and time consuming operation, and is

important only for file systems with large files that are mostly

invariant. In many cases, normal file update and creation will

rebalance your file system over time, without the cost of the

rebalancing.

.RE

.RE

.PP

.RS +3

\fB-v {\fB\fIyes\fR\fR | no}

\fR

.RE

.RS +9

Verify that specified disks do not belong to an existing file

system. The default is \fB-v yes\fR. Specify \fB-v no\fR

only when you want to reuse disks that are no longer needed for an existing

file system. If the command is interrupted for any reason, you must use

the \fB-v no\fR option on the next invocation of the command.

.RE

.SH "Exit status"

.PP

.PP

.RS +3

\fB0

\fR

.RE

.RS +9

Successful completion.

.RE

.PP

.RS +3

\fBnonzero

\fR

.RE

.RS +9

A failure has occurred.

.RE

.SH "Security"

.PP

You must have root authority to run the \fBmmadddisk\fR command.

.PP

You may issue the \fBmmadddisk\fR command from any node in the GPFS

cluster.

.PP

When using the \fBrcp\fR and \fBrsh\fR commands for remote

communication, a properly configured \fB.rhosts\fR 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 the

\fBmmcrcluster\fR or the

\fBmmchcluster\fR command, you must ensure:

.RS +3

.HP 3

1. Proper authorization is granted to all nodes in the GPFS cluster.

.HP 3

2. The nodes in the GPFS cluster can communicate without the use of a

password, and without any extraneous messages.

.RE

.SH "Examples"

.PP

To add the disks whose descriptors are located in \fB./disk_pools\fR

to the file system \fBfs1\fR, and rebalance the existing

files after it is added, issue this command:

.sp

.nf

mmadddisk fs1 -F ./disk_pools -r

.fi

.sp

.PP

The system displays information similar to:

.sp

.nf

GPFS: 6027-531 The following disks of fs1 will be formatted on node

k148n07.kgn.ibm.com:

     gpfs10nsd: size 2202180 KB

Extending Allocation

Map Creating Allocation Map for storage pool 'pool2'

   75 % complete on Thu Feb 16 13:57:52 2006  

  100 % complete on Thu Feb 16 13:57:54 2006 

Flushing Allocation Map for storage pool 'pool2'

GPFS: 6027-535 Disks up to size 24 GB can be added to

storage pool pool2.

Checking allocation map for storagepool system   

  62 % complete on Thu Feb 16 13:58:03 2006  

 100 % complete on Thu Feb 16 13:58:06 2006 

Checking allocation map for storage pool pool1  

  62 % complete on Thu Feb 16 13:58:11 2006  

 100 % complete on Thu Feb 16 13:58:14 2006 

Checking allocation map for storage pool pool2  

  63 % complete on Thu Feb 16 13:58:19 2006  

 100 % complete on Thu Feb 16 13:58:22 2006 

GPFS: 6027-1503 Completed adding disks to file system fs1. m

madddisk: 6027-1371 Propagating the cluster configuration

data to all affected nodes.  This is an asynchronous

process. 

Restriping fs1 ... 

Thu Feb 16 13:58:48 est 2006: mmcommon pushSdr_async:

mmsdrfs propagation started 

Thu Feb 16 13:58:52 est 2006: mmcommon pushSdr_async:

mmsdrfs propagation completed; 

mmdsh rc = 0 

GPFS: 6027-589 Scanning file system metadata, phase 1 ...  

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: 6027-589 Scanning file system metadata, phase 4 ...  

GPFS: 6027-552 Scan completed successfully. GPFS: 6027-565

Scanning user file metadata ...   

  68 %  complete on Thu Feb 16 13:59:06 2006

 100 %  complete on Thu Feb 16 13:59:07 2006 

GPFS: 6027-552 Scan completed successfully. 

Done

.fi

.sp

.SH "See also"

.PP

mmchdisk Command

.PP

mmcrnsd Command

.PP

mmdeldisk Command

.PP

mmlsdisk Command

.PP

mmlsnsd Command

.SH "Location"

.PP

\fB/usr/lpp/mmfs/bin\fR

.PP