In a documentation it is stated that the module usb-storage is required to read data on a USB storage device.
On my system (Knoppix 3.9) I have usbcore and not usb-storage.
Is it equivalent?
Hereafter a few lines from dmesg.
-----------
Initializing USB Mass Storage driver...
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
------------
Herafter is the list generated by lsmod.

Module Size Used by
usb_storage 63296 0
ipv6 234912 6
snd_ens1371 22880 1
snd_rawmidi 22816 1 snd_ens1371
snd_seq_device 10636 1 snd_rawmidi
snd_ac97_codec 68216 1 snd_ens1371
snd_pcm_oss 47904 0
snd_mixer_oss 18688 1 snd_pcm_oss
snd_pcm 77828 3 snd_ens1371,snd_ac97_codec,snd_pcm_oss
snd_timer 23684 1 snd_pcm
snd_page_alloc 11268 1 snd_pcm
gameport 7552 1 snd_ens1371
snd 46308 10 snd_ens1371,snd_rawmidi,snd_seq_device,snd_ac97_co dec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore 11104 1 snd
radeon 73472 0
drm 58900 1 radeon
lp 13448 0
deflate 6656 0
zlib_deflate 24088 1 deflate
twofish 39680 0
serpent 17408 0
aes_i586 42624 0
blowfish 11904 0
des 15360 0
sha256 12928 0
sha1 12160 0
md5 7680 1
crypto_null 6016 0
autofs4 18820 1
af_packet 20104 0
agpgart 30512 1 drm
natsemi 27616 0
cfi_cmdset_0002 23296 1
cfi_util 7168 1 cfi_cmdset_0002
mtdpart 12288 1 cfi_cmdset_0002
jedec_probe 20352 0
cfi_probe 9984 0
gen_probe 6912 2 jedec_probe,cfi_probe
ichxrom 8576 0
mtdcore 9800 3 mtdpart,ichxrom
chipreg 6656 3 jedec_probe,cfi_probe,ichxrom
map_funcs 5632 1 ichxrom
i2c_i801 11276 0
i2c_core 21248 1 i2c_i801
parport_pc 38596 1
parport 33480 2 lp,parport_pc
8250 41692 0
serial_core 21120 1 8250
ub 18332 0
ohci1394 33028 0
ieee1394 300600 1 ohci1394
usbhid 42176 0
ohci_hcd 21896 0
uhci_hcd 31376 0
usbcore 101496 6 usb_storage,ub,usbhid,ohci_hcd,uhci_hcd
pcmcia 21776 0
yenta_socket 21896 0
rsrc_nonstatic 12160 1 yenta_socket
pcmcia_core 42272 3 pcmcia,yenta_socket,rsrc_nonstatic
apm 22252 2
rtc 13772 0
ext3 124552 0
jbd 65060 1 ext3
reiserfs 232304 1