Standard NSD file

%pool: pool=system blockSize=256K layoutMap=cluster allowWriteAffinity=no
%pool: pool=datapool blockSize=2M layoutMap=cluster allowWriteAffinity=yes writeAffinityDepth=1 blockGroupFactor=256

# gpfstest9
%nsd: nsd=node9_meta_sdb device=/dev/sdb servers=gpfstest9 usage=metadataOnly failureGroup=101 pool=system
%nsd: nsd=node9_meta_sdc device=/dev/sdc servers=gpfstest9 usage=metadataOnly failureGroup=101 pool=system

%nsd: nsd=node9_data_sde2 device=/dev/sde2 servers=gpfstest9 usage=dataOnly failureGroup=1,0,1 pool=datapool
%nsd: nsd=node9_data_sdf2 device=/dev/sdf2 servers=gpfstest9 usage=dataOnly failureGroup=1,0,1 pool=datapool

# gpfstest10
%nsd: nsd=node10_meta_sdb device=/dev/sdb servers=gpfstest10 usage=metadataOnly failureGroup=201 pool=system
%nsd: nsd=node10_meta_sdc device=/dev/sdc servers=gpfstest10 usage=metadataOnly failureGroup=201 pool=system

%nsd: nsd=node10_data_sde2 device=/dev/sde2 servers=gpfstest10 usage=dataOnly failureGroup=2,0,1 pool=datapool
%nsd: nsd=node10_data_sdf2 device=/dev/sdf2 servers=gpfstest10 usage=dataOnly failureGroup=2,0,1 pool=datapool

# gpfstest11
%nsd: nsd=node11_meta_sdb device=/dev/sdb servers=gpfstest11 usage=metadataOnly failureGroup=301 pool=system
%nsd: nsd=node11_meta_sdc device=/dev/sdc servers=gpfstest11 usage=metadataOnly failureGroup=301 pool=system

%nsd: nsd=node11_data_sde2 device=/dev/sde2 servers=gpfstest11 usage=dataOnly failureGroup=3,0,1 pool=datapool
%nsd: nsd=node11_data_sdf2 device=/dev/sdf2 servers=gpfstest11 usage=dataOnly failureGroup=3,0,1 pool=datapool

https://www.ibm.com/support/knowledgecenter/en/STXKQY_4.2.3/com.ibm.spectrum.scale.v4r23.doc/bl1adv_standardnsdfile.htm

Simple NSD File

This section describes a simple NSD file with an example.

The following is an example of a preferred simple IBM Spectrum Scale™ NSD file:

There are 7 nodes, each with 6 disk drives to be defined as NSDs. All information must be continuous with no extra spaces

# cat /var/lib/ambari-server/resources/gpfs_nsd
DISK|compute001.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg
DISK|compute002.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg
DISK|compute003.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg
DISK|compute005.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg
DISK|compute006.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg
DISK|compute007.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg

If you want to select disks such as SSD drives for metadata , add the label -meta to those disks.

In a simple NSD file, add the label meta for the disks that you want to use as metadata disks, as shown in the following example. If -meta is used, the Partition algorithm is ignored.

 

 

# cat /var/lib/ambari-server/resources/gpfs_nsd
DISK|compute001.private.dns.zone:/dev/sdb-meta,/dev/sdc,/dev/sdd
DISK|compute002.private.dns.zone:/dev/sdb-meta,/dev/sdc,/dev/sdd
DISK|compute003.private.dns.zone:/dev/sdb-meta,/dev/sdc,/dev/sdd
DISK|compute005.private.dns.zone:/dev/sdb-meta,/dev/sdc,/dev/sdd
DISK|compute006.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd
DISK|compute007.private.dns.zone:/dev/sdb,/dev/sdc,/dev/sdd

In the simple NSD file, /dev/sdb from compute001, compute002, compute003, and compute005 are specified as meta disks in the IBM Spectrum Scale file system.

The partition algorithm is ignored if the nodes listed in the simple NSD file do not match the set of nodes that will be used for the NodeManager service. If nodes that are not NodeManagers are in the NSD file or nodes that will be NodeManagers are not in the NSD file, no partitioning will be done.