Re: how to remove freebsd when it is running

In the past, when dealing with ancient systems that did not have good iloms, where I wanted to upgrade but my coworker had (for example) provisioned too small a / filesystem, I’ve had luck in moving the MFSBSD binaries into /boot and rebooting — and then ssh’ing into the resulting memory-file-system OS and sweeping the floor under me, but your mileage may vary and you should probably try this on a VM first.

This is absolutely don’t-try-this-at-home-kids networking, but also, something I would do as a cool presentation at a conference if someone asked.  (I’ll be at BSDCan, I really should have submitted this).

-Dan

> On Apr 17, 2024, at 16:10, Polytropon <freebsd@edvax.de> wrote:
> 
> On Wed, 17 Apr 2024 22:21:15 +0800, hlyg wrote:
>> my freebsd 13 is installed at flash disk of dell thin client
>> 
>> it doesn't work well, i want to remove it
>> 
>> "dd if=/dev/zero of=/dev/ada0 count=1000 ..." doesn't work, freebsd 
>> doesn't allow
> 
> This is intended, because you cannot write to a disk currently
> in use by the OS.
> 
> 
> 
>> according to dell manual, i shall be able to enter bios by pressing F2 
>> before bsd booting so that i can set boot sequence  to boot from usb 
>> disk, but i can't enter bios, pressing F2 doesn't work
> 
> Reboot the system with a FreeBSD live system from USB stick
> and then use the dd command to remove the FreeBSD installation.
> 
> But instead of removing it, why not use the installer of the
> new OS you want to install to your Dell thin client to first
> remove the existing partition(s), then install the new OS?
> That approach should be much easier.
> 
> 
> 
>> it's not easy for me to open case and dismount disk
> 
> That surely isn't needed.
> 
> 
> 
> -- 
> Polytropon
> Magdeburg, Germany
> Happy FreeBSD user since 4.0
> Andra moi ennepe, Mousa, ...
>