Displaying NSD information
Use mmlsnsd command to display the NSD information and analyze the cluster details pertaining to NSDs.
Use the mmlsnsd command to display
information about the currently defined NSDs in the cluster. For example,
if you issue mmlsnsd, your output may be
similar to this:
File system Disk name NSD servers
---------------------------------------------------------------------------
fs1 t65nsd4b (directly attached)
fs5 t65nsd12b c26f4gp01.ppd.pok.ibm.com,c26f4gp02.ppd.pok.ibm.com
fs6 t65nsd13b c26f4gp01.ppd.pok.ibm.com,c26f4gp02.ppd.pok.ibm.com,c26f4gp03.ppd.pok.ibm.com
This output shows that:
- There are three NSDs in this cluster: t65nsd4b, t65nsd12b, and t65nsd13b.
- NSD disk t65nsd4b of file system fs1 is SAN-attached to all nodes in the cluster.
- NSD disk t65nsd12b of file system fs5 has 2 NSD server nodes.
- NSD disk t65nsd13b of file system fs6 has 3 NSD server nodes.
If you need to find out the local device names for these
disks, you could use the -m option on the mmlsnsd command.
For example, issuing:
mmlsnsd -m
Disk name NSD volume ID Device Node name Remarks
-----------------------------------------------------------------------------------------
t65nsd12b 0972364D45EF7B78 /dev/hdisk34 c26f4gp01.ppd.pok.ibm.com server node
t65nsd12b 0972364D45EF7B78 /dev/hdisk34 c26f4gp02.ppd.pok.ibm.com server node
t65nsd12b 0972364D45EF7B78 /dev/hdisk34 c26f4gp04.ppd.pok.ibm.com
t65nsd13b 0972364D00000001 /dev/hdisk35 c26f4gp01.ppd.pok.ibm.com server node
t65nsd13b 0972364D00000001 /dev/hdisk35 c26f4gp02.ppd.pok.ibm.com server node
t65nsd13b 0972364D00000001 - c26f4gp03.ppd.pok.ibm.com (not found) server node
t65nsd4b 0972364D45EF7614 /dev/hdisk26 c26f4gp04.ppd.pok.ibm.com From
this output we can tell that:
- The local disk name for t65nsd12b on NSD server c26f4gp01 is hdisk34.
- NSD disk t65nsd13b is not attached to node on which the mmlsnsd command was issued, nodec26f4gp04.
- The mmlsnsd command was not able to determine the local device for NSD disk t65nsd13b on c26f4gp03 server.
To find the nodes to which disk t65nsd4b is
attached and the corresponding local devices for that disk, issue:
mmlsnsd -d t65nsd4b -M
Disk name NSD volume ID Device Node name Remarks
-----------------------------------------------------------------------------------------
t65nsd4b 0972364D45EF7614 /dev/hdisk92 c26f4gp01.ppd.pok.ibm.com
t65nsd4b 0972364D45EF7614 /dev/hdisk92 c26f4gp02.ppd.pok.ibm.com
t65nsd4b 0972364D45EF7614 - c26f4gp03.ppd.pok.ibm.com (not found) directly attached
t65nsd4b 0972364D45EF7614 /dev/hdisk26 c26f4gp04.ppd.pok.ibm.com
From this output we can tell that NSD t65nsd4b is:
- Known as hdisk92 on node c26f4gp01 and c26f4gp02.
- Known as hdisk26 on node c26f4gp04
- Is not attached to node c26f4gp03
To
display extended information about a node's view of its NSDs, the mmlsnsd
-X command can be used:
mmlsnsd -X -d "hd3n97;sdfnsd;hd5n98"
Disk name NSD volume ID Device Devtype Node name Remarks
---------------------------------------------------------------------------------------------------
hd3n97 0972846145C8E927 /dev/hdisk3 hdisk c5n97g.ppd.pok.ibm.com server node,pr=no
hd3n97 0972846145C8E927 /dev/hdisk3 hdisk c5n98g.ppd.pok.ibm.com server node,pr=no
hd5n98 0972846245EB501C /dev/hdisk5 hdisk c5n97g.ppd.pok.ibm.com server node,pr=no
hd5n98 0972846245EB501C /dev/hdisk5 hdisk c5n98g.ppd.pok.ibm.com server node,pr=no
sdfnsd 0972845E45F02E81 /dev/sdf generic c5n94g.ppd.pok.ibm.com server node
sdfnsd 0972845E45F02E81 /dev/sdm generic c5n96g.ppd.pok.ibm.com server node From
this output we can tell that:
- Disk hd3n97 is an hdisk known as /dev/hdisk3 on NSD server node c5n97 and c5n98.
- Disk sdfnsd is a generic disk known as /dev/sdf and /dev/sdm on NSD server node c5n94g and c5n96g, respectively.
- In addition to the preceding information, the NSD volume ID is displayed for each disk.
Note: The -m, -M and -X options
of the mmlsnsd command can be very time
consuming, especially on large clusters. Use these options judiciously.