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)
DELL M630 BLADE SERVER x2 XEON E5-2660V3 @ 2.6GH H730 PERC HDD CADDIES 16GB FC
$50.00
Cisco UCS 5108 Blade Server Chassis Enclosure N20-C6508 4x PSU 8x Fans 2x Fabric
$139.99
Dell PowerEdge FX2s CTO Blade 4 Slot 2U Chassis 2x 2000W
$399.00
Dell PowerEdge M620 Blade Server
$39.99
Dell Poweredge FC630 Blade Server BAREBONES No CPU, No HDD, No RAM
$75.00
Dell PowerEdge M630 Blade Server 1x Xeon E5-2630 v4 CPU / Motherboard P/N 0R10KG
$69.99
2 x HP ProLiant BL460c (447707-B21) Blade Servers No RAM No HDD
$30.00
Dell PowerEdge M620 0F9HJC Blade Server 2*E5-2670 2.60GHz 192GB RAM 2*300GB SAS
$103.99
Dell PowerEdge M620 Blade Server 2x E5-2670 2.6Ghz 16-Cores 256gb 2x 146gb 15k
$244.99
UCSB-B200-M4 UCS Blade Server, 2x E5-2667 V3, 256GB RAM DDR4, 2x 300GB Drives
$299.99