When you connect to your ESXi host and you launch esxtop. You look at the esxtop output and it is not displaying as it should. Instead, it is displaying like in the below screenshot:
Your esxtop output will be displayed correctly if you are using a terminal emulator that defaults to xterm as the TERM environment variable. Some terminal emulators will use another terminal emulator value by default, eg. xterm-256color. ESXi does not map xterm-256color to one of the values it knows, so it doesn’t know how to display the output.
There is a KB article that explains how to resolve:
The value of the environment variable TERM is used by the server to control how input is recognized by the system, and what capabilities exist for output.
Let us have a look first what the TERM variable is in my case:
Shell
1
echo$TERM
I am receiving the following output:
My terminal emulator tries to connect to the endpoint (ESXi) with xterm-256color. Now let’s take a look at what values this endpoint does support:
So all of the above is possible to assign to TERM. The value my terminal emulator uses is not among the supported terminfo types. So the ESXi host cannot map to any of the known and thus does not know how to display the esxtop info correctly.
When we update the TERM environment variable to xterm and try to run esxtop again, the output will show nicely formatted.
Default
1
2
TERM=xterm
echo$TERM
Let’s check esxtop again to make sure the outcome is as expected:
Sometimes you want/need use iPerf to test the nic speed between two ESXi hosts. I did because I was seeing a NIC with low throughput in my lab.
How can we test raw speeds between the two hosts? iPerf comes to the rescue. I was looking on how to do this on an ESXi host. I doesn’t come as a surprise that I found the solution here at William Lams’ virtuallyghetto.com. Apparently iperf has been added to ESXi since 6.5 U2. You used to have to copy iperf to iperf.copy. In ESXi 7.0 that has been done for you, although you will need to look for /usr/lib/vmware/vsan/bin/iperf3.copy
ESXi host 1 (iperf server)
Disable the firewall:
Shell
1
esxcli network firewall set--enabled false
Change to the directory containing the iperf binary
Shell
1
cd/usr/lib/vmware/vsan/bin/
Execute iPerf as server
Shell
1
./iperf3.copy-s-B10.11.6.171
Overview of the used parameters:
-s
will start iperf as server
-B
defines the IP the iperf server will listen to
Disable the firewall
Shell
1
esxcli network firewall set--enabled false
ESXi host 2 (iperf client)
Change to the directory containing the iperf binary
Shell
1
cd/usr/lib/vmware/vsan/bin/
Execute iPerf as client
Shell
1
./iperf3.copy-i1-t10-c10.11.6.171-fm
Overview of the used parameters:
-i
will determine the interval of reporting back
-t
time iperf will be running
-c
client ip, will force the usage of the correct vmkernel interface
-fm
defaults to kbit/s, adding m will use mbit/s
Don’t forget to re-enable the firewall on both systems.
The following powershell snippet is going to unconfigure the diagnostic coredump partition using the esxcli version 2 cmdlet. The second part will reconfigure the diagnostic partition with the ‘smart’ option so that an accessible partition is chosen.