Result of mount:
rootfs on / type rootfs (rw,relatime,size=1796268k,nr_inodes=217410)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
devpts on /dev/pts type devpts (rw,relatime,mode=600,ptmxmode=000)
tmpfs on /dev/shm type tmpfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/sdb1 on /mnt/sdb1 type ext2 (rw,relatime,barrier=1)
/dev/sdb1 on /home type ext2 (rw,relatime,barrier=1)
/dev/sdb1 on /opt type ext2 (rw,relatime,barrier=1)
/dev/loop0 on /tmp/tcloop/wireless-3.0.3-tinycore type squashfs (ro,relatime)
/dev/loop1 on /tmp/tcloop/libiw type squashfs (ro,relatime)
/dev/loop2 on /tmp/tcloop/wireless_tools type squashfs (ro,relatime)
/dev/loop3 on /tmp/tcloop/openssl-0.9.8 type squashfs (ro,relatime)
/dev/loop4 on /tmp/tcloop/wpa_supplicant type squashfs (ro,relatime)
/dev/loop5 on /tmp/tcloop/wifi type squashfs (ro,relatime)
/dev/loop6 on /tmp/tcloop/libxcb type squashfs (ro,relatime)
/dev/loop7 on /tmp/tcloop/libxml2 type squashfs (ro,relatime)
/dev/loop8 on /tmp/tcloop/glib2 type squashfs (ro,relatime)
/dev/loop9 on /tmp/tcloop/shared-mime-info type squashfs (ro,relatime)
/dev/loop10 on /tmp/tcloop/Xorg-7.6-lib type squashfs (ro,relatime)
/dev/loop11 on /tmp/tcloop/graphics-libs-1 type squashfs (ro,relatime)
/dev/loop12 on /tmp/tcloop/gdk-pixbuf2 type squashfs (ro,relatime)
/dev/loop13 on /tmp/tcloop/pango type squashfs (ro,relatime)
/dev/loop14 on /tmp/tcloop/expat2 type squashfs (ro,relatime)
/dev/loop15 on /tmp/tcloop/fontconfig type squashfs (ro,relatime)
/dev/loop16 on /tmp/tcloop/pixman type squashfs (ro,relatime)
/dev/loop17 on /tmp/tcloop/cairo type squashfs (ro,relatime)
/dev/loop18 on /tmp/tcloop/atk type squashfs (ro,relatime)
/dev/loop19 on /tmp/tcloop/gtk2 type squashfs (ro,relatime)
/dev/loop20 on /tmp/tcloop/dbus type squashfs (ro,relatime)
/dev/loop21 on /tmp/tcloop/dbus-glib type squashfs (ro,relatime)
/dev/loop22 on /tmp/tcloop/libnotify type squashfs (ro,relatime)
/dev/loop23 on /tmp/tcloop/curl type squashfs (ro,relatime)
/dev/loop24 on /tmp/tcloop/libasound type squashfs (ro,relatime)
/dev/loop25 on /tmp/tcloop/firefox type squashfs (ro,relatime)
/dev/loop26 on /tmp/tcloop/i2c-3.0.3-tinycore type squashfs (ro,relatime)
/dev/loop27 on /tmp/tcloop/graphics-3.0.3-tinycore type squashfs (ro,relatime)
/dev/loop28 on /tmp/tcloop/xf86-video-intel type squashfs (ro,relatime)
/dev/loop29 on /tmp/tcloop/Xorg-fonts type squashfs (ro,relatime)
/dev/loop30 on /tmp/tcloop/Xorg-7.6-bin type squashfs (ro,relatime)
/dev/loop31 on /tmp/tcloop/Xorg-7.6 type squashfs (ro,relatime)
/dev/loop32 on /tmp/tcloop/mirrors type squashfs (ro,relatime)
/dev/loop33 on /tmp/tcloop/sqlite3 type squashfs (ro,relatime)
/dev/loop34 on /tmp/tcloop/nspr type squashfs (ro,relatime)
/dev/loop35 on /tmp/tcloop/nss type squashfs (ro,relatime)
/dev/loop36 on /tmp/tcloop/flash10 type squashfs (ro,relatime)
/dev/loop37 on /tmp/tcloop/kmaps type squashfs (ro,relatime)
/dev/loop38 on /tmp/tcloop/ncurses-common type squashfs (ro,relatime)
/dev/loop39 on /tmp/tcloop/ncurses type squashfs (ro,relatime)
/dev/loop40 on /tmp/tcloop/libogg type squashfs (ro,relatime)
/dev/loop41 on /tmp/tcloop/libtheora type squashfs (ro,relatime)
/dev/loop42 on /tmp/tcloop/libmad type squashfs (ro,relatime)
/dev/loop43 on /tmp/tcloop/cdparanoia type squashfs (ro,relatime)
/dev/loop44 on /tmp/tcloop/faac type squashfs (ro,relatime)
/dev/loop45 on /tmp/tcloop/glib1 type squashfs (ro,relatime)
/dev/loop46 on /tmp/tcloop/gtk1 type squashfs (ro,relatime)
/dev/loop47 on /tmp/tcloop/MPlayer-svn-gtk1 type squashfs (ro,relatime)
/dev/loop48 on /tmp/tcloop/qt-4.x-base type squashfs (ro,relatime)
/dev/loop49 on /tmp/tcloop/qt-4.x-xml type squashfs (ro,relatime)
/dev/loop50 on /tmp/tcloop/smplayer type squashfs (ro,relatime)
/dev/loop51 on /tmp/tcloop/p7zip type squashfs (ro,relatime)
/dev/loop52 on /tmp/tcloop/p7zip-full type squashfs (ro,relatime)
/dev/loop53 on /tmp/tcloop/syslinux type squashfs (ro,relatime)
/dev/loop54 on /tmp/tcloop/nano type squashfs (ro,relatime)
/dev/loop55 on /tmp/tcloop/OSS-modules-3.0.3-tinycore type squashfs (ro,relatime)
/dev/loop56 on /tmp/tcloop/OSS type squashfs (ro,relatime)
/dev/loop57 on /tmp/tcloop/ruby type squashfs (ro,relatime)
/dev/loop58 on /tmp/tcloop/ruby-dev type squashfs (ro,relatime)
/dev/sda1 on /mnt/sda1 type ext2 (rw,relatime,barrier=1)
/dev/loop59 on /tmp/tcloop/zlib_base-dev type squashfs (ro,relatime)
/dev/loop60 on /tmp/tcloop/util-linux_base-dev type squashfs (ro,relatime)
/dev/loop61 on /tmp/tcloop/linux-3.0.1_api_headers type squashfs (ro,relatime)
/dev/loop62 on /tmp/tcloop/libpng_base-dev type squashfs (ro,relatime)
/dev/loop63 on /tmp/tcloop/jpeg_base-dev type squashfs (ro,relatime)
/dev/loop64 on /tmp/tcloop/imlib2_base-dev type squashfs (ro,relatime)
/dev/loop65 on /tmp/tcloop/gcc_base-dev type squashfs (ro,relatime)
/dev/loop66 on /tmp/tcloop/freetype_base-dev type squashfs (ro,relatime)
/dev/loop67 on /tmp/tcloop/eglibc_base-dev type squashfs (ro,relatime)
/dev/loop68 on /tmp/tcloop/e2fsprogs_base-dev type squashfs (ro,relatime)
/dev/loop69 on /tmp/tcloop/sed type squashfs (ro,relatime)
/dev/loop70 on /tmp/tcloop/popt type squashfs (ro,relatime)
/dev/loop71 on /tmp/tcloop/pkg-config type squashfs (ro,relatime)
/dev/loop72 on /tmp/tcloop/patch type squashfs (ro,relatime)
/dev/loop73 on /tmp/tcloop/make type squashfs (ro,relatime)
/dev/loop74 on /tmp/tcloop/m4 type squashfs (ro,relatime)
/dev/loop75 on /tmp/tcloop/grep type squashfs (ro,relatime)
/dev/loop76 on /tmp/tcloop/gmp type squashfs (ro,relatime)
/dev/loop77 on /tmp/tcloop/mpc type squashfs (ro,relatime)
/dev/loop78 on /tmp/tcloop/mpfr type squashfs (ro,relatime)
/dev/loop79 on /tmp/tcloop/binutils type squashfs (ro,relatime)
/dev/loop80 on /tmp/tcloop/gcc_libs type squashfs (ro,relatime)
/dev/loop81 on /tmp/tcloop/gcc type squashfs (ro,relatime)
/dev/loop82 on /tmp/tcloop/gawk type squashfs (ro,relatime)
/dev/loop83 on /tmp/tcloop/flex type squashfs (ro,relatime)
/dev/loop84 on /tmp/tcloop/compiletc type squashfs (ro,relatime)
Result of ls -l /mnt
total 8
drwxr-xr-x 9 root root 4096 Oct 3 21:49 sda1/
drwxr-xr-x 7 root root 4096 Oct 3 21:50 sdb1/
drwxr-xr-x 2 root root 40 Oct 4 18:39 sr0/
drwxr-xr-x 2 root root 40 Oct 4 19:50 test/
Result of cat /etc/mtab | grep /mnt/sda1: nothing