missing partition in server centos 6.1 - linux

Question

I used the command df-h on my centos 6.1
here's the output
[root#localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
50G 2.3G 45G 5% /
tmpfs 5.9G 0 5.9G 0% /dev/shm
/dev/sda1 485M 35M 425M 8% /boot
/dev/mapper/VolGroup-lv_home
2.0T 199M 1.9T 1% /home
i found out that the hard disk is two terabyte. but when I used the command cat /proc/partitions | more
here's the output
[root#localhost sysconfig]# cat /proc/partitions | more
major minor #blocks name
8 0 4293656576 sda
8 1 512000 sda1
8 2 2146970624 sda2
253 0 52428800 dm-0
253 1 14417920 dm-1
253 2 2080120832 dm-2
you could see on the first line. it is 4396.7 GB . why is it i could only see is 2TB? how could i find my missing another 2TB and make it a partition.
I also use the command lsblk
here is the output
[root#localhost ~]# lblsk
-bash: lblsk: command not found
[root#localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO MOUNTPOINT
sda 8:0 0 4T 0
ââsda1 8:1 0 500M 0 /boot
ââsda2 8:2 0 2T 0
ââVolGroup-lv_root (dm-0) 253:0 0 50G 0 /
ââVolGroup-lv_swap (dm-1) 253:1 0 13.8G 0 [SWAP]
ââVolGroup-lv_home (dm-2) 253:2 0 2T 0 /home
sr0 11:0 1 1024M 0
using the parted /dev/sda i type the print free command
here's the output
(parted) print free
Model: DELL PERC 6/i (scsi)
Disk /dev/sda: 4397GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
32.3kB 1049kB 1016kB Free Space
1 1049kB 525MB 524MB primary ext4 boot
2 525MB 2199GB 2198GB primary lvm
2199GB 4397GB 2198GB Free Space

Answer 1

I was wrong, sorry. As you can see in parted print free output you have 2 MBR partitions - boot and lvm and 2198GB free space (last row).
If you want to use all of your space you have to use GPT partitions. These partitions as opposed to MBR partition that can only address up to 2TB, can address your whole disk and up to 8 ZiB (zebibytes).
You can try to convert MBR partition table to GPT (example 1, example 2), though I strongly recommend to backup your data.

Answer 2

You are using tools showing info from different layers of your system and interpreting it wrong.
df, according to man page, will display the space available on all currently mounted file systems.
/proc/partitions holds info about partitions on your drive - physical device. This file shows you size of your drive as number of blocks. Usually, on HDD block size is a size of sector - 512 bytes.
So, sda size of 4293656576 is size in blocks, not kilobytes.
4293656576 blocks = (4293656576 / 2 ) kilobytes = 2146828288 KiB = 2047.375 GiB, or 2198.352 GB.
Assuming 1 GiB = 1 * 2^30, 1 GB = 1 * 10^3.
If you want to see size of your disk use fdisk -l <device name>.