I recently facing the issue, datastore's are not visible after upgrade the Esxi hosts from 6.0 to 6.7 U3.

I have performed the esxi host upgrade via update manager.  No issue was triggered during the upgrade.

Basic troubleshooting, I have rescanned the storage adapters but no luck.

How to rescan the storage: 

      > selected the esxi host and right click > choose storage > select rescan storage.

wait for complete the rescan and verify the esxi host.

How to check the NIC cards status.

     > selected the esxi host > go to configuration tab> Choose physical adapter option under networking

verified the any Nics/cards are down or not. Looks everything was good.

So I decided to check HBA card details via command line

> Login putty session of esxi host

> Run the below command.

 # vmkchdev -l |grep vmhbaX

vmkchdev -l |grep vmhba  Get HBA Vendor ID (VID), Device ID (DID), Sub-Vendor ID (SVID), and Sub-Device ID (SDID) using the vmkchdev command

for Example output 

--------------------------------------------------

vmkchdev -l |grep vmhba1

000:16.0 10df:e200 10df:e280 vmkernel vmhba1

In this example, the values are:

VID = 10df

DID = e200

SVID = 10df

SDID = e280

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Please use below URL to check compatibility versions 

https://www.vmware.com/resources/compatibility

> Download the latest firmware version  and upload into esxi host.

> There are multiple ways to firmware zip file into esxi host. I uploaded through WINSCP.

>  Login putty session of esxi host.

      # esxcli Software Vib Install -d path

      # esxcli software vib install -d /datastore/Broadcome-flx-ipfc_12.8.

      # reboot

> please reboot the esxi host after installed firmware version.

> Issue got fixed. Now able to see all existing datastore and seems to be fine.

>  All datastore's are came backup after update the firmware of HBA card. 

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