.TH mmdf 02/16/06
mmdf Command
.SH "Name"
.PP
\fBmmdf\fR - Queries available file space on a GPFS file
system.
.SH "Synopsis"
.PP
\fBmmdf\fR \fIDevice\fR [\fB-d\fR | \fB-F\fR |
\fB-m\fR] [\fB-P\fR \fIPoolName\fR] [\fB-q\fR]
.SH "Description"
.PP
Use the \fBmmdf\fR command to display available file space on a
GPFS file system. For each disk in the GPFS file system, the
\fBmmdf\fR command displays this information, by failure group and storage
pool:
.RS +3
.HP 3
\(bu The size of the disk.
.HP 3
\(bu The failure group of the disk.
.HP 3
\(bu Whether the disk is used to hold data, metadata, or both.
.HP 3
\(bu Available space in full blocks.
.HP 3
\(bu Available space in fragments.
.RE
.PP
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.
.PP
For the file system, the \fBmmdf\fR command displays:
.RS +3
.HP 3
\(bu The total number of inodes and the number available.
.RE
.PP
The \fBmmdf\fR command may be run against a mounted or unmounted file
system. 
.RS +3
\fBNote:\fR
.RE
.RS +9
The command is I/O intensive and should be run when the system load is
light.
.RE
.SH "Parameters"
.PP
.RS +3
\fB\fIDevice\fR
\fR
.RE
.RS +9
The device name of the file system to be queried for available file
space. 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
.SH "Options"
.PP
.RS +3
\fB-d
\fR
.RE
.RS +9
List only disks that can hold data.
.RE
.PP
.RS +3
\fB-F
\fR
.RE
.RS +9
List the number of inodes and how many of them are free.
.RE
.PP
.RS +3
\fB-m
\fR
.RE
.RS +9
List only disks that can hold metadata.
.RE
.PP
.RS +3
\fB-P \fIPoolName\fR
\fR
.RE
.RS +9
Lists only disks that belong to the requested storage pool.
.RE
.PP
.RS +3
\fB-q
\fR
.RE
.RS +9
For quick access to the file space information, list the data collected
from the most recent synchronization period.
.PP
With this flag, the values recorded by the \fBmmdf\fR command are
synchronized only at the last invocation of the \fBsyncd\fR daemon on the
node where the command is issued.
.RE
.PP
The default is to list all disks.
.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
If you are a root user:
.RS +3
.HP 3
1. You may issue the \fBmmdf \fR command from any node in the GPFS
cluster.
.HP 3
2. 
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 either the
\fBmmcrcluster\fR
or
\fBmmchcluster\fR command, you must ensure:
.RS +3
.HP 3
a. Proper authorization is granted to all nodes in the GPFS cluster.
.HP 3
b. The nodes in the GPFS cluster can communicate without the use of a
password, and without any extraneous messages.
.RE
.RE
.PP
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 \fBmmdf \fR command was
issued.
.SH "Examples"
.RS +3
.HP 3
1. To query all disks in the \fBfs1\fR file system that can hold data,
issue this command:
.sp
.nf
mmdf fs1 -d
.fi
.sp
.sp
The system displays information similar to:
.sp
.nf
disk    disk size failure holds   holds  free KB in     free KB
name      in KB   group  metadata data  full blocks in fragments
------- --------- ------ -------- ----- ------------- ----------
gpfs1nsd  8886720    4003 yes     yes   8733184 (98%)   632 (0%)
gpfs2nsd  8886720    4003 yes     yes   8879360 (100%)  440 (0%)
gpfs3nsd  8886720    4003 yes     yes   8884224 (100%)  440 (0%)
gpfs4nsd  8886720    4003 yes     yes   8884224 (100%)  440 (0%)
gpfs5nsd  8886720    4003 yes     yes   8884224 (100%)  440 (0%)
         --------                       -------------- ---------
(total)  44433600                     44265216 (100%)  2392 (0%)
.fi
.sp
.HP 3
2. To query all disks in the \fBfs1\fR file system that can hold
metadata, issue this command:
.sp
.nf
mmdf fs1 -m
.fi
.sp
.sp
The system displays information similar to:
.sp
.nf
disk   disk size failure holds  holds   free KB in   free KB
name    in KB    group metadata data  full blocks in fragments
--------  ------- ----- ------- -----  -------------  -----------
Disks in storage pool: system
hd2vsdn01  8880128  2   yes     yes   8610304 (97%)  13640 (0%)
hd3vsdn01  8880128  2   yes     yes   8610816 (97%)  13072 (0%)
hd4vsdn01  8880128  2   yes     yes   8611840 (97%)  11784 (0%)
hd5vsdn01  8880128  2   yes     yes   8613120 (97%)  13560 (0%)
hd18vsdn02 8880128 4005 yes     yes   8657408 (97%)  13816 (0%)
hd17vsdn02 8880128 4005 yes     yes   8658176 (98%)  12968 (0%)
          -------------              -------------- -----------
(pool total) 631430168              619939328 (98%) 629872 (0%)
Disks in storage pool: sp1
          -------------            --------------- ------------
(pool total)         0                      0 (0%)       0 (0%)
          =============            =============== =============
(total)       631430168           619939328 (98%)   629872 (0%)
.fi
.sp
.HP 3
3. To query \fBfs1\fR for inode information, issue this command:
.sp
.nf
mmdf fs1 -F
.fi
.sp
.sp
The system displays information similar to:
.sp
.nf
Inode Information
------------------
Total number of inodes: 33792
Total number of free inodes: 33752
.fi
.sp
.RE
.SH "See also"
.PP
mmchfs Command
.PP
mmcrfs Command
.PP
mmdelfs Command
.PP
mmlsfs Command
.SH "Location"
.PP
\fB/usr/lpp/mmfs/bin\fR
.PP