Boot from second hdd on grub2

Question

First of all, Sorry for bad English.

I did a lot of searching on Google with no luck. My second HDD is located in a the CD-ROM slot using a "SATA 2nd HDD caddy for 12.7mm Universal CD/DVD-ROM". Primary harddisk is SANDISK 240GB SSD.

Firstly, I try to select boot from second HDD which was recognized by BIOS as SATA ODD but no option to select this HDD.

Secondly, Try to configure grub to get acces to this hdd but it doesnt't listed on grub via ls command. Only hd0 and proc are listed. If I plug USB it shows as hd1 but still there is no entry for my second hdd.

Thirdly, which is I found out luckily , booting from USB for "BIOS implementing Test Suite" to check my CPU clock rate and then I saw an option "Boot from Second Hard Drive" so I just entered and it was booted.

Now I don't want to use USB at all time when I want to boot from second harddisk so I tried to boot syslinux from grub with no success. It was just go back to grub.

Do you have any advice to solve this problem?

UPDATE: Thanks @Hennes for spell checking. Now, when I boot from usb ,its grub can see the second HDD even if I boot from my primary SSD (without shutdown just using grub prompts) I can see the second HDD from grub. But vice versa, didn't happen same. Booting from SSD and then using grub command I boot from USB (without shutdown) and its grub also doesn't see my second HDD. I think it is related to my BIOS but currently there is no update release for my laptop.

NOTE: The second HDD has no bad block/sector or any other issue to block it to boot.

--My PC is Dell Inspiron N4050 and with upgraded 8GB RAM@1333MHz (as two slot)

Answer 1

Finally, I solved this annoying problem. The problem is BIOS.

As I said before, Whenever I boot from usb it sees but not for harddisk. But Actually not. The Boot Order from my BIOS setup configure is like: "HDD","USB","CD-DVD","Floopy","LAN". Also I can select only one time boot from its two keys selection which are F2 (Enter Setup) and F12(One Time Boot Select) when BIOS startup. So that I never used F12 to boot from HDD (It's default). And then mistakenly I press Hard-disk from F12 menu. And Viola! the grub sees both hdd and ssd. But still I can't figure-out why boot from F12 menu lists both HDD and SSD and why directly boot from HDD doesn't lists secondary hdd.

So I need to figure-out its why but still I don't know from where I do start. But this solution is applicable answer for me. If you use Dell Inspiron N4050 to boot from hdd, you can use this solution. It works without USB devices.