.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