[CentOS] How bad is "rm -rf /" ?

Sat Feb 6 04:48:57 UTC 2016
Gordon Messmer <gordon.messmer at gmail.com>

On 02/05/2016 06:31 PM, Mark LaPierre wrote:
> So let me get this straight.  You are saying that you can make changes
> to the MB ROM/EPROM/whatever hardware the vendor uses, by issuing an
> erase command on a hard drive?

No, but you can erase the UEFI variables by issuing "rm" on them if the 
OS presents them as a part of the filesystem, as Linux does. You know, 
the UNIX design philosophy of "everything is a file"?

Not all of the filesystem represents sectors on a hard drive.

> You might be able to trash the system on the HD to a point that it is
> unrecoverable.  I will believe that.
>
> When you're done trashing the system you just have to reinstall the
> system just like you would with a clean new HD.

https://github.com/systemd/systemd/issues/2402

On some systems, wiping the UEFI variables renders the system completely 
unbootable.  It shouldn't, but there are some bad UEFI implementations 
out there.

> All that UEFI crap is built into the MB in Read Only hardware.  A new HD
> does not come with any of the UEFI files or directories already on the
> disk.  All that is created at the initial install.  Blowing them away
> with a remove command does nothing to the MB hardware because it's Read
> Only hardware.

The UEFI configuration is entirely RW.