BOOT PROBLEM WITH AN EXTERNAL SSD USB DISK (WITH A LINUX SYSTEM,
GPT/BIOS SETUP AND GRUB2)
I prepared the following text to address different recipients I intend to
submit it to: Manjaro Linux, Adata ssd, Asus, Grub2 and Super Grub2
Disk. I hope it is adquate for a first aproach of the problem.
For additional technical data about my system see
http://pastebin.com/nfDms8Mc(search for inxi, lspci, lsusb, dmidecode).
I have a Asus-N55SL-S1094V notebook with Windows7 on the internal HDD
and Manjaro Linux on a Adata External SSD SE720 USB3 with a GPT/Bios
setup as per 'Installation to SSD (quick guide) - Manjaro Linux' and Grub2.
1 - My boot problem:
- power on
- Adata shows on boot menu
- if Adata selected I get a line with GRUB followed by garbage
- if I enter key 'e' (edit), 'c' (command mode), or any other key,
Windows7 boots.
- I have no problem booting from other USB external media drives or pens
(not ssd and with normal MBR/Bios setup)
2 - Workaround to boot (time consuming, defeats the purpose of a quick
boot frm a ssd, my motivation to buy one):
- power on
- select 'Enter setup' (bios) instead of Adata
- on 'boot order' choose Adata to boot before internal HDD
- Save and Exit
- on boot menu select Adata
- now success: Grub 2 menu shows
3 - I noticed when I enter bios:
- 'HDD bbs priorities' shows WD..(internal HDD), then other external USB
media, but no Adata SSD.
- 'Floppy drive bbs priorities' shows Adata SSD.
- other settings as normal: AHCI interface, EFI disabled
- bios up to date.
4 - There is no problem when I restart from within the system (Manjaro
Linux) instead of power off and then power on.
With above workaround (2) I can boot from one USB3 and 2 USB2 ports
but not from the other USB3 port which allows charge of usb media even
when the notebook is shutdown.
5 - Power on and booting with 'Super Grub2 Disk' detects Adata SSD as a
floppy with partions 'fd0,gpt1',...,'fd0,gpt4' and no boot.
If (workaround):
- power on
- Enter setup (bios)
- set 'boot order' to Adata before HDD
- Save and Exit
- on boot menu choose CD drive (Super Grub2 Disk)
- this time 'Super Grub2 Disk' detects correctly Adata SSD as
'hd2,gpt1', ...,'hd2,gpt4'
6 - I used another notebook, an Asus A6Tc (older), with same problem:
if in boot menu I select Adata I get I line with 'GRUB:' only and no way to boot;
I have to enter bios setup and afterwords select Adata.