EQL: Disabling Delayed Ack and Increasing iSCSI Login Timeout in vSphere ESXi 5.x for Use with EqualLogic SANs

For each host that has an iSCSI connection to the SAN, perform the following : 

Disabling Delayed Ack :

1. In the vSphere Client, ensure the host is selected on the left and then click on the Configuration tab
2. Click on Storage Adapters underneath Hardware
3. Find your iSCSI Software Adapter in the list, right click it and choose Properties
4. Click on the Dynamic Discovery tab
5. Click on the Settings button
6. Click on the Advanced button
7. Scroll down until you see DelayedAck
8. Uncheck Inherit from Parent
9. Uncheck DelayedAck
10. Click the OK button
11. Reboot the host

Increasing iSCSI Login Timeout :

1. Connect to the host via SSH
   • For more information on using SSH on your vSphere ESXi server : www.dell.com/support/article/SLN283377
2.  Find your vmhba for your iSCSI Software Adapter :
3. # esxcfg-scsidevs -a | grep -i "iscsi software adapter"
4. # esxcli iscsi adapter param set -A <vmhba obtained from step 2> -k LoginTimeout -v <seconds>
5. NOTE : Maximum seconds value is 60.
6. Example :
   • # esxcli iscsi adapter param set -A vmhba43 -k LoginTimeout -v 60
7. Change iSCSI login timeout value :
8. Reboot the host