Android 4.1.1 system is consuming 4GB of my memory? I bought an Android 4.1.1 tablet, the ad said "comes with 8 GB". But when I go to the system configuration I get:

INTERNAL 
1,18 GB total
Apps 0,90 GB
Available 161 MB

NAND FLASH
Total 4,55 GB
Free 4,17 GB

I ask the vendor where is the 8 GB, and they said: "the tablet comes with physical 8GB, but the Android System makes a partition for different purposes (Recovery, Loader, Apps, etc.) letting available for the user only 4 GB. The others partitions are not visible for the user. This is the same for all Android devices".

They are telling me the truth? or just are a bunch of liars and sold me an 4GB tablet ?

Android 4.1.1 
Core 3.0.8+
Compilation P758.6.01.01.20
Brand: NOBLEX - Model: T7014AR 
(official specification: RAM 1GB - Internal 8GB)
http://www.noblex.com.ar/tablets/T7014AR

Thanks a lot.



EDIT:

u0_a78@android:/ $ df
Filesystem             Size   Used   Free   Blksize
/dev                  443.2M  36.0K  443.2M   4096
/mnt/asec             443.2M  0.0 K  443.2M   4096
/mnt/obb              443.2M  0.0 K  443.2M   4096
/system               607.4M  440.2M  167.2M  1024
/data                 1.2 G   1.0 G  153.8M   4096
/cache                629.9M  16.5M  613.4M   4096
/mnt/external_sd      941.7M  16.0K  941.7M   16384
/mnt/sdcard           4.5 G   382.1M  4.2 G   8192
/mnt/secure/asec: Permission denied
/mnt/asec/com.robotinvader.fooding-1  36.5M  34.8M  1.7 M   4096
/mnt/asec/com.vkcode.SpaceTube-1  14.2M  12.6M  1.6 M   4096
1|u0_a78@android:/ $
Yes, you have an 8GB tablet.  How Android partitioning works is there is a NAND flash chip, and then it's basically split up into system storage (/system) and otherwise, and user accessible storage (/data) and possibly (in some cases), /sdcard (note that I'm talking about the emulated legacy SD Card, not your expansion slot.

So, when they say it's an 8GB tablet, they're correct.

EDIT:

Looking at your df output...  Blksize refers to the maximum length, in bytes, of a file storage block.  You don't have to worry about that column.  What we're focused on is all the other partitions.  Let's start at the top:

/dev contains device nodes.  Don't worry about the reported size - it has no effect on your storage.

/mnt/asec and /mnt/obb are each partitioned with 443.2MB.  With those two partitions (required by the system), you have 886.4MB, rounding up.

/system (where Android lives) is partitioned at 607.4MB, which will bring our total up to 1.5GB.

/data is where all user preferences and settings are stored.  When you do a factory reset, you are wiping the /data partition.  Adding in the 1.2GB from there, we have a total of 2.7GB.

/cache is also required by Android, and with a 629.9MB partition, we're at 3.3GB.

/mnt/external_sd is your external SD card.  Forget about that for now.

/mnt/sdcard is the internal SD card - a partition of user accessible storage in the internal memory.  It's set at 4.5GB - which is what your vendor is reporting.

Add all these partitions together, and we have a total of 7.8GB which is correct for an 8GB tablet.

Storage manufacturers report storage in decimal, meaning 1000MB = 1GB.  However, in binary, 1024MB = GB, so that's why you have a discrepancy.