Nix Server

Important!

• For this to work, this configuration depends on the existence of the /etc/nixos/vars and /etc/nixos/tokens directories.
  • Their existence makes these single configuration.nix files more general purpose.

Creating variables

Unfortunately, using vim or echo to create variables will append a newline character at the end of the file and cause issues.

For example, if you want to create a /etc/nixos/vars/timezone file, then you should perform the following command:

sudo sh -c 'printf "America/New_York" > /etc/nixos/vars/timezone'

Setting Up

Allowing SSH connections

• Objective: Make server SSH-able through my own domain (lambda.lv)
  • Ultimate goal is to run the following command: ssh lv@lambda.lv

1. Enable OpenSSH in /etc/nixos/configuration.nix:

   services.openssh = {
     enable = true;
     settings.PermitRootLogin = "no";
   }
       

2. Port forward the server with internal & external ports 22 as per IANA. Make sure to use TCP protocol.
3. Find out your IP address. The way I did it was through

   curl ifconfig.me
       

4. Add a AAAA record in my DNS settings for my lambda.lv domain.

Troubleshooting

Fan on slot 4 does not stop spinning!

Problem

• Upon receiving power, fan on slot 4 turns on at full speed
• Server does not need to be ‘on’, just needs to have electricity
• Issue is not physical fan
  • Proof: Despite switching the slots of the fans, the fan on slot 4 continues to be the one spinning

Relevant error message

Upon running diagnostics, the following error was received

ePSA 4233.3 - Failure

Error code : 2000-8007 Validation : 74986 Msg : IPMI Sep 11 2023 02:10:28 Warning. System Board Fan4: sensor for System Board, warning event.

Technical Support will need this information to diagnose the problem. Please record the above Error and Validation codes. Service Tag 9K0LV12, BIOS 2.9.0

Do you want to continue testing?

Potentially related error in logs?

IPMI Nov 14 2023 19:25:22 Critical. Chipset Err: Critical Event sensor PCI PERR (Bus 0 Device 5 Function 0) was asserted.

Solution

Sources

• As per this thread on Dell Community forum, this is a firmware issue and not a physical hardware issue.
  • Solution is to downgrade firmware to 2.41.40
  • Other sources backing this
    • A Dell Community forum thread having fixed the issue by downgrading firmware
    • A Dell Community forum with the same error listing firmware that is known to be problematic, although no official solution was given in that thread
• Apparently, fan 4’s role is to cool the iDRAC

My version

• Upon writing experiencing this issue, my firmware is at
  • BIOS: 2.9.0
  • iDRAC Settings Version: 1.65.65.04
  • iDRAC Firmware Version: 2.65.65 (Build 15)

Performing solution

• Install RHEL 7.9 from this page
  • Search and download iDRAC with Lifecycle Controller v2.41.40 for RHEL7
  • Install firmware using chmod +x iDRAC-firmwarefile.bin then ./iDRAC-firmwarefile.bin