We were running voice tests for months now and recently had to power down the ESXi host to install it in a different rack. Can you confirm if the CDRs get cleared when the server is powered down?

7. Troubleshooting Troubleshooting
1

If you had the CDR enabled, then they are stored on the host at /lib/tb/toolpack/setup/12358/cdr_logs/

https://docs.telcobridges.com/tbwiki/Toolpack:Enabling_CDR_C
https://docs.telcobridges.com/tbwiki/TMG:Retrieve_Text_CDR