6.0.1

Adjust Queue Depth for QLogic, Emulex, and Brocade HBAs
If you are not satisfied with the performance of your hardware bus adapters (HBAs), change the maximum
queue depth on your ESXi host.
The maximum value refers to the queue depths reported for various paths to the LUN. When you lower this
value, it throttles the host's throughput and alleviates SAN contention concerns if multiple hosts are
overutilizing the storage and are filling its command queue.
To adjust the maximum queue depth parameter, use the vCLI commands.
In the procedure, --server=server_name specifies the target server. The specified target server prompts you
for a user name and password. Other connection options, such as a configuration file or session file, are
supported. For a list of connection options, see Getting Started with vSphere Command-Line Interfaces.
Prerequisites
Install vCLI or deploy the vSphere Management Assistant (vMA) virtual machine. See Getting Started with
vSphere Command-Line Interfaces. For troubleshooting, run esxcli commands in the ESXi Shell.
Procedure
1 Verify which HBA module is currently loaded by entering the following command:
esxcli --server=server_name system module list | grep module
Use one the following options for module.
Option Description
qla
QLogic
qln
QLogic native drivers
lpfc
Emulex
bfa
Brocade
2 Adjust the queue depth for the appropriate module.
esxcli --server=server_name system module parameters set -p parameter=value -m module
Use the following strings for the parameter and module options.
String Description
-p ql2xmaxqdepth=value
-m qla2xxx
QLogic
-p ql2xmaxqdepth=value
-m qlnativefc
QLogic native drivers
-p lpfc0_lun_queue_depth=value
-m lpfc820
Emulex
-p lpfc0_lun_queue_depth=value
-m lpfc
Emulex native drivers
-p bfa_lun_queue_depth=value
-m bfa
Brocade
3 Reboot your host.
4 Verify your changes by running the following command:
esxcli --server=server_name system module parameters list -m=module.
module is an appropriate driver, such as qlnativefc or bfa.
vSphere Troubleshooting
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