Frequently Asked Questions
Kaizen VM Troubleshooting Tips
Last Updated about a month ago
- Google the specific error message, in quotes. E.g. “TX stuck with port_enabled=1: resetting channels”. Also google without quotes, especially if there are machine names, hex addresses, etc. in the message
- If you can’t reach a VM, look at the console:
- can you log in?
- Is it wedged? (e.g. an oops message followed by panic)
- Can you reboot it?
- If you can log in, is sshd turned on?
- Do your security groups allow you to ssh in?
- Run ‘ip addr show’ and see if you have the right IP address.
- Run ‘dmesg’ to print kernel message buffer. Are there any unusual messages or warnings?
- Run ‘ssh -v’ to see why you’re not connecting properly
- Run ‘nc 22’ to see if you can connect to sshd. Hit return to exit. You should see something like: $ nc login.ccs.neu.edu 22SSH-2.0-OpenSSH_7.4 Protocol mismatch
- If you have weird networking things going on, use tcpdump to capture traffic, and download it and look at it with wireshark if you know what you’re doing, or have someone else do it if you don’t. $ sudo tcpdump -i en0 -w /tmp/port80.pcap port 80tcpdump: listening on en0, link-type EN10MB (Ethernet), capture size 262144 bytes^C0 packets captured36 packets received by filter0 packets dropped by kernel$ sudo tcpdump -i en0 -w /tmp/port80.pcap host google.com tcpdump: listening on en0, link-type EN10MB (Ethernet), capture size 262144 bytes^C0 packets captured63 packets received by filter0 packets dropped by kernelThe first captures all traffic until you ^C. The second is all traffic on port 80, the third is all traffic between the machine and google.com. Note that you have to know which interface to capture on - in this case it’s ‘en0’. (that’s mac-specific. Use ‘ip addr show’ to figure out correct interface)