Enabling serial-line logging for an ESXi/ESXi host
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Enabling serial-line logging for an ESXi/ESXi host


Article ID: 344469


Updated On:


VMware vCenter Server VMware vSphere ESXi


It is sometimes helpful to have logs captured independent of disk or network connectivity when troubleshooting issues. Enabling serial logging will send all VMKernel logs (and Service Console for ESX) to the serial port in addition to their normal destination.

For more information on network-based logs, see: For more information on disk-based logs, see Location of log files for VMware products (1021806).


VMware vSphere ESXi 6.5
VMware vSphere ESXi 5.0
VMware ESXi 3.5.x Installable
VMware ESXi 4.0.x Embedded
VMware ESXi 3.5.x Embedded
VMware ESXi 4.1.x Installable
VMware vSphere ESXi 6.0
VMware ESX 4.0.x
VMware ESXi 4.0.x Installable
VMware vSphere ESXi 5.1
VMware vCenter Server 5.5.x
VMware vSphere ESXi 6.7
VMware ESXi 4.1.x Embedded
VMware ESX 4.1.x
VMware vSphere ESXi 7.0.0
VMware ESX Server 3.0.x
VMware ESX Server 3.5.x


Recording logs from an ESXi/ESX host via a serial communications port has several requirements:

  • A remote system is configured to open its serial communications port and record received content to disk.
  • The ESXi/ESX host is connected to the remote system via a Null Modem serial cable.
  • The ESXi/ESX host is configured to open its serial communications port and send logs via that port.

The remote system

The remote system can be another computer such as a spare laptop, desktop, or server that has an RS-232 compliant serial COM port. It can be any running any operating system with any terminal program to read information from the serial port, and requires enough disk storage space to write the messages coming from the serial port to disk.

VMware recommends that the serial port be configured for a baud rate of 115200 bps with No Parity, 8-bit words, and 1 Stop Bit (8N1).

Configuration of third-party terminal software to connect to a serial port or save to disk is outside the scope of this article. Common programs used are Hyperterm or PuTTY for Windows, and Minicom or Seyon for Linux. Refer to the documentation of the terminal software you intend to use to learn how to configure it. For example, see Using PuTTY to capture serial-line logs from ESXi/ESX hosts (1033843).

Configuring the ESXi/ESX host

The ESXi/ESX host must be configured to open a serial communications port and send logs. The process differs for different versions of ESX and ESXi. For more information, see one of these articles:
To configure serial logging on a Cisco UCS blade, see the Cisco Configuration Guide.

Note: The preceding link was correct as of September 10, 2012. If you find the link is broken, provide feedback and a VMware employee will update the link.

Additional Information

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For information on release ESXi 5.5 Please see the documentation center:
Enabling syslog on ESX
Enabling syslog on ESXi 3.5 and 4.x
Location of ESX 3.0-4.1 log files
Location of log files for VMware products
Enabling serial-line logging for ESX and ESXi 4.1
Using PuTTY to capture serial-line logs from ESX/ESXi hosts
Configuring syslog on ESXi
为 ESXi/ESXi 主机启用串行日志记录