[How-To] Boot Entirely from SATA

[WarheadsSE]

I grow tired of saying this:

This SATA method entirely bypasses the NAND & its uboot!

[ldi9999]

If I already have arch installed (the normal way) can I still boot straight to a (different) properly configured sata drive, or will I need to restore the u-boot environment to defaults?

You do not have to restore anything, just need to configure the SATA drive by following the guide. It worked really well.

[ldi9999]

use blparam to edit the bootargs from NAND uboot root=/dev/sdb1 ?

Is there any risk to do so? How can I change it back to /dev/sda1 if it does not work? I'd like to make sure before I try. Thanks.

[WarheadsSE]

Simple, run the same command, but alter it back.

Broken SATA's Cheater method: duplicate USBs & no sata.

[ldi9999]

I installed Archlinux standard way (not entire SATA) on a usb drive. While booting, I have both USB drive and SATA drive attached. SATA drive is taking /dev/sda and USB drive is taking /dev/sdb. I want to change the bootargs to point boot drive, which is USB drive sdb. Since this is not Entire SATA installation, I want to make sure I can still access the unit in case boot fails, in order for me to reverse the change.

Is the the command?

Code: Select all

blparam "bootargs=root=/dev/sdb1"

[WarheadsSE]

ABSOLUTELY NOT

You need to specify the whole replacement for bootargs. That will render you a very interesting pile of uselessness.

[ldi9999]

I understand that bootargs is a environment variable. You can change the value and then save it. U-boot will use it while booting.
Say I change it from /dev/sda1 to /dev/sdb1 and boot failed, as you mentioned I just need to reverse it back. My question is how could I change it back? i.e. Do you mean I can still access the unit via ssh even when booting failed?

Again, this is a standard installation, not Entirely from SATA.

[ldi9999]

WarheadsSE, can you please comment? Thanks.

[WarheadsSE]

Here's the breakdown:
- You want to change to sdb1 for rootfs
- You want to leave SATA attached, thus the above is necessary.

Here's how it can be done:
- use blparam to change the value of root in the bootargs variable.
--- This means `blparam bootargs="entire line here but with root's value changed"`
- Use serial to interrupt & change the value appropriately using the setenv command.
- Boot from SATA and run the command from there.

Here's how it can break:
- there aren't 2 drives, thus /dev/sdb1 is not present, no boot.
- the "second" drive is not an oxnas rootfs, no boot.
- a SATA drive is attached with the magic dust, it will try to boot from SATA, likely no boot.

[ldi9999]

Here's the breakdown:
- You want to change to sdb1 for rootfs
- You want to leave SATA attached, thus the above is necessary.
Correct, sdb1 is current a USB flash drive, which has rootfs and working.

Here's how it can be done:
- use blparam to change the value of root in the bootargs variable.
--- This means `blparam bootargs="entire line here but with root's value changed"`
I think I will take this approach

- Use serial to interrupt & change the value appropriately using the setenv command.
- Boot from SATA and run the command from there.

Here's how it can break:
- there aren't 2 drives, thus /dev/sdb1 is not present, no boot.
I will always have both USB and SATA attached. i.e. /sdb1 is supposed to be USB since SATA always take /sda1
- the "second" drive is not an oxnas rootfs, no boot.
see above
- a SATA drive is attached with the magic dust, it will try to boot from SATA, likely no boot.
What's the reason there is no boot? Is it because the bootargs change to /sdb1?

My last question remains. What if I changed bootargs, attached both drives, and have rootfs on USB (/sdb1), but the system won't boot. How can I reverse the change in bootargs? I do not have serial cable. Ans as you mentioned "a SATA drive is attached with the magic dust, it will try to boot from SATA, likely no boot", which means SATA boot is not an option either.