This message occurring during boot up of KNOPPIX-Live has no deleterious consequences but it is an annoyance.
It is probably an unintended hangover from the HD-installed version which allocates several partitions.
Either ignore it or include a (2nd and) 3rd (and 4th) partition in your boot device, even if it is a USB stick.
Use fdisk* to set /dev/{sda}1 as the KNOPPIX partition type c (being FAT32; or NTFS if you prefer - I've never tried this).
Set /dev/{sda}3 as type 83 (Linux) (at least 400M). Then format it as Reiserfs with mkreiserfs .
It's not obvious to me how (or even whether) the partition is used; but it is made available; and you will boot
without the annoying error message!
(*) Yes: you need to format your intended USB device - from a temporary KNOPPIX USB device is probably your most
convenient method ;o)
COMMODORE VIC-20 COMPUTER SYSTEM UNTESTED
$89.95
commodore 64 computer works recapped in original box
$219.00
Commodore 64c Computer - Tested And Working Great
$140.00
Commodore 64, 128 & C-16 Color S-Video and Audio Adapter W/ Chroma Adjuster
$34.00
Vintage Commodore Amiga 500 Computer Keyboard Model A500 Sold As Is
$199.99
Commodore 1541 Disk Drive for 64 / 128 with Selector Switch + Cables for Repair
$69.99
Commodore SX-64 SX64 Executive Portable Color Computer - See Description
$359.00
Commodore SX-64 Control Panel Door Lot Of (2) SX64 C-64
$29.99
Commodore 64 Computer In Original Box With Power Supply Powers On Untested
$199.99
Vintage Commodore VIC-20 Personal Color Computer in Box W/ Extras
$129.99