Dell EqualLogic PS6210XS EqualLogic Host Integration Tools for Linux Version 1 - Page 41

Excluding a Subnet or Adapter From MPIO, Including or Excluding Specific Host NICs

Page 41 highlights

Excluding a Subnet or Adapter From MPIO Use the rswcli --mpio-exclude (or rswcli -E) command to select the subnets or adapters to exclude from MPIO. You can specify a subnet, an adapter identified by a user-defined string, an IP address, or a MAC address. Dell recommends using a subnet or adapter name based on inclusion/exclusion rules. Including or Excluding Specific Host NICs Include or exclude a host NIC with the IP address of the NIC and a netmask of 255.255.255.255: # ip addr show eth1 3: eth1: mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:31:25:55 brd ff:ff:ff:ff:ff:ff inet x.x.x.xx/16 brd xx.xxx.255.255 scope global eth1 # rswcli --mpio-exclude --net x.x.x.xx --mask 255.255.255.255 Processing mpio-exclude command... Adding x.x.x.xx - 255.255.255.255 to exclude list The mpio-exclude command succeeded. Configuring I/O Path Selection HIT/Linux provides configurable parameters that let you establish path selection policy for the middle tier multipath device. These parameters set load balancing policy and determine number of I/Os to send on each path before switching paths. Load Balancing Policy The default load balancing parameter (--mpio-parameters --dlb) lets you specify the default load balancing policy for MPIO: Round Robin (RR) or Least Queue Depth (LQD). The RR policy rotates among each path to the member sending a fixed number of I/Os to each. The LQD (or queue-length) policy considers the number of outstanding I/Os on that path. Each load balancing policy is implemented by a path selector kernel module. Availability of path selectors depends on your kernel version. If available, LQD is the default policy. If not, HIT/Linux uses RR as the default policy. You can set the load balancing parameter by editing the eql.conf file or with the following RSWCLI command: # rswcli --mpio-parameters --dlb LQD|RR I/O Scheduling The I/O per path parameter lets you specify the number of I/Os to send on each path before switching paths. I/O scheduling is performed above the multipath layer, at the dm-switch layer. The I/O per path parameter (--mpio-parameters --ios) defaults to a value of 16. You can adjust this value in the eql.conf file or with the following RSWCLI command: # rswcli --mpio-parameters --ios=1-1000 Setting Volume-Specific Configuration Parameters The configuration parameters in the MPIO Parameters section are global settings applied to all volumes. The ehcmd command supports volume-specific settings for the following parameters: • EnableMPIO • IOPerPath Configuring Multipath I/O Devices 41

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Excluding a Subnet or Adapter From MPIO
Use the
rswcli --mpio-exclude
(or
rswcli -E
) command to select the subnets or adapters to exclude from MPIO. You can
specify a subnet, an adapter identified by a user-defined string, an IP address, or a MAC address. Dell recommends using a subnet or
adapter name based on inclusion/exclusion rules.
Including or Excluding Specific Host NICs
Include or exclude a host NIC with the IP address of the NIC and a netmask of 255.255.255.255:
# ip addr show eth1
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP
qlen 1000
link/ether 08:00:27:31:25:55 brd ff:ff:ff:ff:ff:ff
inet x.x.x.xx/16 brd xx.xxx.255.255 scope global eth1
# rswcli --mpio-exclude --net x.x.x.xx --mask 255.255.255.255
Processing mpio-exclude command...
Adding x.x.x.xx - 255.255.255.255 to exclude list
The mpio-exclude command succeeded.
Configuring I/O Path Selection
HIT/Linux provides configurable parameters that let you establish path selection policy for the middle tier multipath device. These
parameters set load balancing policy and determine number of I/Os to send on each path before switching paths.
Load Balancing Policy
The default load balancing parameter (
--mpio-parameters --dlb
) lets you specify the default load balancing policy for MPIO:
Round Robin (RR) or Least Queue Depth (LQD). The RR policy rotates among each path to the member sending a fixed number of I/Os
to each. The LQD (or queue-length) policy considers the number of outstanding I/Os on that path.
Each load balancing policy is implemented by a path selector kernel module. Availability of path selectors depends on your kernel version. If
available, LQD is the default policy. If not, HIT/Linux uses RR as the default policy.
You can set the load balancing parameter by editing the
eql.conf
file or with the following RSWCLI command:
#
rswcli --mpio-parameters --dlb
LQD|RR
I/O Scheduling
The I/O per path parameter lets you specify the number of I/Os to send on each path before switching paths.
I/O scheduling is performed above the multipath layer, at the
dm-switch
layer. The I/O per path parameter (
--mpio-parameters
--ios
) defaults to a value of 16. You can adjust this value in the
eql.conf
file or with the following RSWCLI command:
#
rswcli --mpio-parameters --ios=
1-1000
Setting Volume-Specific Configuration
Parameters
The configuration parameters in the MPIO Parameters section are global settings applied to all volumes. The
ehcmd
command supports
volume-specific settings for the following parameters:
EnableMPIO
IOPerPath
Configuring Multipath I/O Devices
41