Logs not visible after downgrading Panorama from 9.0.x to 8.x.x version

• All logs from 9.0.x version are not visible after downgrading Panorama to any PAN-OS versions prior to 9.0 versions.

• M-Series
• Panorama VMs

• The Elastic Search Engine version prior to PAN-OS 9.0 version is v2.2.
• The Elastic Search Engine version after PAN-OS 9.0 version is v5.6.
• The ES indices in v5.6 are different that ES indices of v.2.2.
• When upgrading to PAN-OS 9.0, the migration from v2.2 to v5.6 is done automatically.
• When downgrading from PAN-OS 9.0 to PAN-OS prior to 9.0, the migration from v5.6 to v2.2 must be done manually in order for logs to show up.

1. Migration command: >request logdb migrate lc serial-number <serial#> start

>request logdb migrate lc serial-number <serial-number> start

Success.
Migration Start Request sent to serial <serial-number>.

2.  To check the status of the migration: >>request logdb migrate lc serial-number <serial-number> status

>request logdb migrate lc serial-number <serial-number> status

Slot: all

Migration State: In Progress

Percent Complete: 0.31

Estimated Time Remaining:35 hour(s) 7 min(s)

• As soon as the request logdb migrate lc serial-number <serial-number> start command is entered, the old logs will start showing up, and will not impact the new logs. 
• Also, running this command will not impact the management functionalities such as creating/editing/pushing Template/Device Group