BMITC CO,LTD

On the IBM Storwize v7000 I was told the default settings of the MTU was 9000 Jumbo Frames, while dealing with a problem of one of the VMware hosts dropping one of the iSCSI paths, Support suggested I check the MTU setting on the v7000.

After spending a fair bit of time trying to find out how to check the MTU setting and being previously told by IBM you can't change it I found the following.


Command to view settings
lsportip:

Use the lsportip command to list the Internet Small Computer Systems Interface (iSCSI) Internet Protocol (IP) addresses assigned for each port on each node in the clustered system.

Example command: svcinfo lsportip this will display the following.

I used the -delim to seperate it with :

full command: svcinfo lsportip -delim :

id:node_id:node_name:IP_addressgateway:IP_address_6:prefix_6:gateway_6:MAC:duplex:state:speed:failover:link_state
1:1:node1:::::::e4:1f:13:75:81:xx:Full:unconfigured:1Gb/s:no:active
1:1:node1:::::::e4:1f:13:75:81:xx:Full:unconfigured:1Gb/s:yes:active
2:1:node1:::::::e4:1f:13:75:81:xx:Full:unconfigured:1Gb/s:no:active
2:1:node1:::::::e4:1f:13:75:81:xx:Full:unconfigured:1Gb/s:yes:active
3:1:node1:10.10.11.1:255.255.255.0:10.10.11.254::::00:00:c9:d2:ed:xx:Full:configured:10Gb/s:no:active
3:1:node1:::::::00:00:c9:d2:ed:xx:Full:configured:10Gb/s:yes:active
4:1:node1:10.10.12.1:255.255.255.0:10.10.12.254::::00:00:c9:d2:ed:xx:Full:configured:10Gb/s:no:active
4:1:node1:::::::00:00:c9:d2:ed:xx:Full:configured:10Gb/s:yes:active
1:2:node2:::::::e4:1f:13:75:b0:xx:Full:unconfigured:1Gb/s:no:active
1:2:node2:::::::e4:1f:13:75:b0:xx:Full:unconfigured:1Gb/s:yes:active
2:2:node2:::::::e4:1f:13:75:b0:xx:Full:unconfigured:1Gb/s:no:active
2:2:node2:::::::e4:1f:13:75:b0:xx:Full:unconfigured:1Gb/s:yes:active
3:2:node2:10.10.11.2:255.255.255.0:10.10.11.254::::00:00:c9:d9:4a:xx:Full:configured:10Gb/s:no:active
3:2:node2:::::::00:00:c9:d9:4a:xx:Full:configured:10Gb/s:yes:active
4:2:node2:10..10.12..2:255.255.255.0:10.10.12.254::::00:00:c9:d9:4a:xx:Full:configured:10Gb/s:no:active
4:2:node2:::::::00:00:c9:d9:4a:xx:Full:configured:10Gb/s:yes:active


to see the NIC setting select the appropriate id this can be done by doing the following command:

full command: svcinfo lsportip 1 where 1 is the ethernet port id this will display something similar to the following.

id 1
node_id 2
node_name node2
IP_address
mask
gateway
IP_address_6
prefix_6
gateway_6
MAC e4:1f:13:75:xx:xx
duplex Full
state unconfigured
speed 1Gb/s
failover no
mtu 1500
link_state active


You can see that the MTU is 1500 on the 1Gbs interfaces it is also 1500 on the 10Gbs interfaces

id 3
node_id 2
node_name node2
IP_address 10.10.11.2
mask 255.255.255.0
gateway 10.10.11.254
IP_address_6
prefix_6
gateway_6
MAC 00:00:c9:d9:xx:xx
duplex Full
state configured
speed 10Gb/s
failover no
mtu 1500
link_state active

To make changes to these setting use svctask cfgportip command.