How to verify serial port ok from hypervisor CLI?

[BorgSquirrel]

I am having problem with a modem that refuses to work in a VM after change of hypervisor hardware. As a part of the troubleshooting I would like to get a COM port console in the ESXi CLI (such as TeraTerm, PuTTY, HyperTerm etc) so I can verify that the COM port is working and that the hypervisor is able to pass AT commands to the modem. Please note I am NOT asking about serial port inside a VM at this point.

Grep'ing dmesg for "serial" I get these lines. Not sure if they indicate any real errors or if they are expected. It does seem end with both ports being added to devices that the hypervisor

WARNING: VMB_SERIAL: 87: Invalid serial port config: Mem-mapped to addr 0x0.

WARNING: VMB_SERIAL: 168: ACPI SPCR table contains an invalid serial port configuration; ignoring the table.

TSC: 204652 cpu0:1)BootConfig: 190: serialUntrusted = TRUE

TSC: 207154 cpu0:1)BootConfig: 193: serialPolledIRQ = FALSE

0:00:00:00.000 cpu0:1)WARNING: Serial: 185: Invalid serial port config: mem-mapped to addr 0x0.

0:00:00:00.000 cpu0:1)Serial: 792: The ACPI SPCR table contains an invalid serial port config and will be ignored:

0:00:00:08.393 cpu0:65536)CpuSched: 692: user latency of 65555 serialLogger 0 changed by 65536 bootstrap -6

2019-01-18T09:40:05.263Z cpu0:65536)SerialDev: 237: Added serial device uart0, index 11, id 0

2019-01-18T09:40:05.263Z cpu0:65536)SerialDev: 237: Added serial device uart1, index 12, id 1

grep for tty:

TSC: 155634 cpu0:1)BootConfig: 133: tty1Port = default (1)

TSC: 158264 cpu0:1)BootConfig: 136: tty2Port = default (1)

2019-01-18T09:40:05.263Z cpu0:65536)TTY: 263: Allocated 2 out of 2 ttys

[vmrale]

Hi,

maybe this KBs could help You configure serial port communication between ESXi host and a console.

Enabling serial-line logging for an ESXi/ESXi host

VMware Knowledge Base

Enabling serial-line logging for ESXi 5.x and 6.0

https://kb.vmware.com/s/article/1033888​

[BorgSquirrel]

Sorry for the extremely late reply to this, I made the mistake to update my login email address and thereby lost access to VMTN VMware community and internal support has taken up until now to fix it...

I ended up opening a support ticket with VMware regarding this issue. There is no way to verify or interact with com ports from CLI. The issue, unfortunately and embarrassingly, self-resolved at some point... We have no idea what the root cause was.