Switch shuts down with message [EANV-1006], 9272,, CRITICAL, VDX6720-60, C2: HW ASIC Chip fault. Type = 0x2a, Error = Critical Parity Errors. Monitor session is used on ports 1/0/21-1/0/30. When the switch goes down, packet loss goes through the second one.
The EANV-1006 is due to parity errors detected in the ASIC. Typically, a reboot should clear it. If it's still happening after reboot, then it will need to be replaced. Also, ensure that your firmware is on 4.1.3d which is the last supported NOS version for the 6720 platform.
Regarding the packet loss, it's possible the buffers are getting overun resulting in RX discards (tail drops) since it's the only path for all traffic.