ubuntu add second disk

1, sudo fdisk -l

root@ubuntu:~/pubchem/process_sdf# fdisk -l

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000b6fa8

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 488396799 243947521 5 Extended
/dev/sda5 501760 488396799 243947520 8e Linux LVM

Disk /dev/sdb: 250.0 GB, 250000000000 bytes
255 heads, 63 sectors/track, 30394 cylinders, total 488281250 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x41ab2316

Device Boot Start End Blocks Id System
/dev/sdb1 63 80324 40131 12 Compaq diagnostics
/dev/sdb2 * 80325 481949999 240934837+ fd Linux raid autodetect
/dev/sdb3 481966065 488263544 3148740 fd Linux raid autodetect
/dev/sdb4 481950061 481966064 8002 5 Extended
/dev/sdb5 481950063 481966064 8001 8e Linux LVM

Partition table entries are not in disk order

Disk /dev/sdc: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00055dc9

Device Boot Start End Blocks Id System
/dev/sdc1 * 63 488392064 244196001 8e Linux LVM