Imagine you have a vSAN infrastructure and at some point, a diskgroup fails but errors are reported on the disks. With this tool, we can analyze the logs exported from the ESXi host on which the diskgroup resides and identify on which physical disks I / O errors have been highlighted
If an ESXi 5.1 host does not successfully install, serial line logging can be configured when booting the installer using advanced kernel boot-time parameters. This takes effect for the current boot, and does not persist across future reboots. To enable serial-line logging during installation:
At the Loading ESXi installer screen, press Shift+O.
At the prompt, append the advanced option to specify a serial port after runweasel:
> runweasel debugLogToSerial=1 logPort=com1
Press Enter to boot.
Logging starts after the first loading progress bar finishes.