USB Live system for emergency use

This file os bogus:

...
    <resources os="Linux" arch="amd64">
        <j2se version="1.5+"/>
        <nativelib href="release/Linux_x86_64.jar"/>
    </resources>
    <application-desc>
        <argument>192.168.1.208</argument>
        <argument>7578</argument>
        <argument>mwpZ7aJoRsuEFgfo</argument>
        <argument>DBmld581xDCFhVqKdsqC3yy9jFYpcQXY000</argument>
    </application-desc>
</jnlp>

It is missing the mandatory definition of the main class in application-desc <main-class>some.java.class.with.a.main.method</main-class>

If you really want to try use it: Download https://192.168.1.208/Java/release/Linux_x86_64.jar or https://192.168.1.208/Java/release/Win64.jar

and try to run it with

 java -jar /Linux_x86_64.jar 192.168.1.208 7578 mwpZ7aJoRsuEFgfo DBmld581xDCFhVqKdsqC3yy9jFYpcQXY000

and see, if it has a main class defined in its meta-info. (Arguments neet to be changed from the JNLP file).

But we are getting off topic. if you want to continue with that issue, send me a private message or start a new thread.

Zitat von bvrulez

Thanks! Yes, I know it's bootable I just wanted to find out why/if qemu works. Also, I wonder if installing to a USB stick on another machine will work. Or do I need to run the installer from the server I want to use the USB on? Because my server is headless I would like to prepare the stick on another linux.

You can create the USB-stick on any computer and just plug it into your server. make sure it boots from USB.

Zitat von bvrulez

Did not know about this option

Suggest to follow the OMV documentation at https://openmediavault.readthe…on_usb.html?highlight=usb

Zitat von bvrulez

I already found this. Also, this should be the best solution for my original problem: Using OMV on USB as an emergency SSH for headless machines that wont boot up. Sorry I did not think of if myself!

What happens if the OMV on USB you are using on a headless machine doesn't have the correct network interface setup for that machine? If it's headless and you don't have out of band (like ipmi) way to see the console, how do you see anything?

Zitat von chente

Could something like this be a solution? A USB KVM extender over ethernet. Whenever physical distance allows it, logically. In this case 120m.

https://cablematic.com/es/prod…0UKarXh3jEGxoCboIQAvD_BwE

Well sure that could work. If I had to do something like that I would probably go for one of those new PiKVM things. But in my use case, that device would cost almost as much as the server did. Fortunately, my server has a working SOL console and I don't even need ssh to get to it.

I didn't check the price on what you linked. A decently fitted out PiKVM costs more than the $162US I paid for my entire server, less drives.

The question is what you are trying to achieve. If you just want to ssh into the server (after changing the boot USB-stick) having an USB-stick which starts an ssh daemon is ok. You will be able to access your data, but not the boot device.

If you want to debug the boot process (or even change BIOS settings) you need something like ILO, ipmi, a kvm-extender or monitor + keyboard i.e. hardware.

Zitat von bvrulez

I don't know. This was the problem I immediately saw when installing OMV6 on the stick. So, Zoki s answer is wrong in that regard, right? But what exactly is the "network interface setup"? I mean does it go for a specific hardware?

On the other hand the OMV6 stick I just generated did not boot up my old Acer E3-111 where I generated it - due to Secure Boot. I am actually not able to change Secure Boot in the BIOS, it seems. I have no clue whether this will also be an issue on the server. I mean I can find out by putting a monitor on. But it is always a hassle. It is a tower with 9 drives in it which is laying on a high board on the top of my flat's hallway. I usually take a stairway and hold the monitor while also holding the keyboard...

I'll give an example of the problem using my own machines.

I currently run OMV on a USB stick on a Chenbro NR12000 server. I don't remember what ethernet NICs it uses though. If I take that USB stick to my old retired headless ASRock server and boot it, it will boot all the way. But since it's headless I have no monitor or keyboard to interact with it. So the thinking is I can ssh in and work that way. But the ethernet NICs on the ASRock aren't the same as those in the Chenbro. So there is no network connectivity. To fix the networking problem I need to reconfigure the network interface using omv-firstaid using the console. But it's headless so I can't do that unless I plug in a monitor and keyboard. Not convenient.

However, since the machine has an out of band serial over LAN ipmi console running on another dedicated NIC, I can use ipmitool from another machine on the network to get connected to the console, log in and run omv-first-aid. Most users, however, don't have ipmi capable machines so they are stuck.

One way to solve the NIC issue (what is the IP-address of the server today) is to have IPs assigned via DHCP and look into your router to find the assigned address. If your router is somewhat clever, you can even use the name, the server (the usb stick) advertises during requesting a dhcp lease.

Zitat von Zoki

One way to solve the NIC issue (what is the IP-address of the server today) is to have IPs assigned via DHCP and look into your router to find the assigned address. If your router is somewhat clever, you can even use the name, the server (the usb stick) advertises during requesting a dhcp lease.

Sorry, but you don't understand what the possible problem could be. It's not about what IP address is on the network configuration of the OMV running on the USB stick.

Assume the USB stick was setup and running on a machine that has an Intel NIC in it. You take it to another headless machine that has a Real-Tec Nic in it boot it. It will likely boot all the way to the console login screen which you can not see because it's headless. But the networking can't possibly work because OMV is still running on the Intel NIC driver. So you get no IP address on the NIC and can't ssh in. Dead end.

To fix this you need access to the console so you can log in, run omv-firstaid, and reconfigure the network interface which will detect the NIC being different and load the correct driver. But it's headless so you can't do this. Dead end.

Without an out of band console being available (like SOL via ipmi) you have nothing to work with until you attach a monitor and keyboard.

It might depend on exactly what you need to use this rescue USB stick for, but there may be better choices than an OMV installation on USB.

SystemRescueCD on a USB stick might offer more tools.

https://www.system-rescue.org/…ue-on-a-USB-memory-stick/

Are you sure that sshd is running on that IP address? What are the contents of the sshd config file?

Also see:

https://wasteofserver.com/systemrescuecd-6-1-x-and-sshd/