Slow storage device discovery causes bootbank/scratch to not get mounted

Products

• VMware vSphere ESXi

Issue/Introduction

As a result of slow device discovery, the LUN might not be available. The slow discovery might be caused by such issues as slow login to target ports or fabric delays.

Environment

• VMware vSphere ESXi 6.x
• VMware vSphere ESXi 7.0

Resolution

To compensate for possible delays, you can configure device path discovery wait time.

1. Install ESXi on a Boot LUN.
   
   
2. During the ESXi boot, configure the boot option devListStabilityCount=10 (10 Seconds) by pressing Shift+O.

ESXi boots with bootbank mounted to the right volume.

3. Edit /bootbank/boot.cfg to add the devListStabilityCount=10 entry to the kernelopt field.

For example, kernelopt=installerDiskDumpSlotSize=2560 no-auto-partition devListStabilityCount=10.

4. Reboot the ESXi host several times to make sure that it boots successfully.
   
   
5. Verify Boot from SAN on iSCSI and Fibre Channel protocols.