If you want to mount a partition upon startup in linux

You have to enter your partition information to /etc/fstab file. Then your disk will be mounted automatically!

Just go for following step:

• First take back up of /etc/fstab

  sudo cp /etc/fstab /etc/fstab.backup
  

• Execute following command to get your partition UUID information that will help you to configure /etc/fstab file.

  sudo blkid
  

  Search for your partition's UUID which you want to mount automaticall. Your HDD partitions shouls be displayed like:

  /dev/sda1: LABEL="Backup" UUID="00A0CE7EA0CE7A24" TYPE="ntfs"
  /dev/sda5: LABEL="40GBTWO" UUID="00A0CE7EA0CE7A24" TYPE="ntfs" 
  /dev/sda6: UUID="7550252c-3da7-4cd9-8da3-71e9ba38e74a" TYPE="ext4" 
  /dev/sda7: UUID="088fd084-a011-4896-aa93-c0caaad60620" TYPE="swap" 
  /dev/sdb1: LABEL="SaurK" UUID="0DB6254A58CEF6F7" TYPE="ntfs"
  

  and so on. It is just an example but format will be same.
• Now copy the UUID of the partitions which you want to insert in /etc/fstab file.
• Now open /etc/fstab file and insert entry for your HDD partitions on the last line of /etc/fstab file. Take help from previous entry, for format etc:

  sudo gedit /etc/fstab
  

  When opened your entry would be like this:

  UUID=<your_UUID_for_Disk_partitions> /media/<location_where_you_want_to_mount>             ntfs    errors=remount-ro 0
  

  Just an example:

  UUID=00A0CE7EA0CE7A24 /media/Backup               ntfs    errors=remount-ro 0
  

  you may have to replace ntfs to ext4 or fat32 according to the file system of your partition. It displays in blkid output.
• Now create location where to mount your disk partitions. Create a folder for each partitions to mount. ((note: a directory may be already created, if so ignore this step.) For example:

  sudo mkdir /media/Backup
  

• Then execute this command once finished:

  sudo mount -a
  

You can refer this link for further help: Auto mounting with /etc/fstab Hope it works for you..

From:
http://askubuntu.com/questions/343438/why-are-partitons-not-automatically-mounting