VMware ESXi Initiator settings for iSCSI

Applicable ESXi versions: All

When using VMware ESXi systems with Zadara VPSAs, we recommend that the timeout values indicated below are set accordingly.

These values are changed for all iSCSI connection types (Software Adapter or Hardware). From the Advanced Options option for that Adapter type under Storage Adapters. 

Note: that after modification you must reboot the ESXi host to enforce these settings.

For ESXi 6.7 please note the UI location differs - Storage Adapters, Static Discovery, Advanced

Also, this shows how the settings can be changed per connection rather than globally

The recommended ESXi config values are:

• LoginRetryMax: 4
• LoginTimeout: 20 seconds
• NoopTimeout:
  • For versions prior to VMware ESXi 6.5.0, 5969303 - 120 seconds
  • For VMware ESXi 6.5.0, 5969303 onwards - 30 seconds
• RecoveryTimeout: 40 seconds

Note: Additionally each Virtual Guest should also be adjusted with guest disk-timeout set at 120 seconds.

Setup for Windows Server Failover Clustering and Microsoft Cluster Service:

If you are using Failover Clustering or Microsoft Cluster Services the recommended value for “Disk I/O timeout" is 120 seconds.

This is configured in the Windows registry here: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk\TimeOutValue

Other information regarding VMware ESXi / vSphere configuration settings when using WSFC or MSCS can be found here.

VMware Tools

Please note: the changes in timeout that VMware tools applies here are independent of iSCSI or Fibre Channel storage usage, both are block storage.

Where VMware tools is installed, disk timeout settings are applied. (Note: VMware releases can change configurations from version to version, at the time of writing the below are correct).

For Windows guests with VMware Tools installed, the disk timeout option as seen in the registry setting

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk\TimeOutValue is set to 60 seconds. This should be amended to 120 (ie: seconds).

Note: Where VMware Tools is not in use this value is not present so should be created (as a new dword value) and set to 120 (seconds).

For Linux guests with VMware Tools, the disk timeout option is amended to 180 seconds from the default 60 seconds and this does not require changing.

Note: If not using VMware Tools on the linux guest machine please amend to 120 seconds, this setting will differ between Linux variants ie: for CentOS - see /sys/block/<disk>/device/timeout , for Ubuntu it can be changed via udev -

eg:

Create a file /etc/udev/rules.d/20-zadara-timeout.rules
and add this line
KERNEL=="sda", SUBSYSTEM=="block", RUN+="/bin/sh -c '/bin/echo 180 > /sys$DEVPATH/device/timeout'"

Regardless of Linux variant, please ensure your change persists through reboots.