[lubuntu-users] Boot from SD card? Why not?

[Nio Wiklund]

Den 2016-06-05 kl. 07:16, skrev Basil Fernie:
> As always, I am asking for something so simple, so obvious, that it
> cannot be possible... or can it?
>
> I want to install Lubuntu 16.04 to the SDHC card in a laptop and make it
> bootable, so that I can run and work with the laptop without an internal
> or external hard drive.
>
> Background: Someone gave me a Samsung V511 or similar, with quite a nice
> spec but a very dead HDU and battery pack. Rather than spend money
> restoring it, she bought a new laptop.
>
> Obviously I ran a few versions of Linux through it, booting from USB
> sticks. Would be rather nice on my desk, I thought, leaving my Lenovo to
> be truly portable. But how about booting from an SDHC card as a
> semi-permanent installation? Fast, quiet, power-mingy, enough space on a
> 16 or 32GB card for core apps and quite a lot of working data for
> various projects which could of course be archived onto the external
> terabyte-class USD 3.0 drive. No searching for ports and pushing/pulling
> things in and out... Poor man's SSD-plus-personal cloud, anyone?
>
> Lubuntu 16.04 LTS beckoned with its "Startup Disk Creator" option under
> System Tools. The whole process ran beautifully, with the 16GB SDHC
> Level10 being recognised as a legitimate target for the installation
> from ISO, and the installation concluded without demur or any error
> messages noted.
>
> However booting failed with an "Operating system not found" message. The
> Samsung's boot options menu offers half a dozen USB devices, none of
> which does the trick.
>
> Before i throw any more time at this  idea, can someone tell me if it is
> inherently impossible because an SDHC cannot be Grubbed or whatever, or
> is it just an outdated unimaginative BIOS chip on the Samsung which
> could be flashed into the 21st century, 2nd decade?
>
> Thanks as always,
>
> Basil Fernie
>

Hi Basil,

I can boot from SD and SD micro cards, but 'not everywhere'. Some card 
adapters work, some work for read/write but do not work for booting. I 
would say many USB adapters work: I can boot from cards in small 
adapters as well as boxes for several card models (not only SD).

I tried now (just in order to reply) in the built-in slots in two 
laptops, and they did *not* boot from an SD card that boots via USB 
adapters. I know, that some computers boot from cards in built-in slots.

If you have too few USB ports on the computer, I can tell you that it 
works to boot an SD card via a USB adapter via a USB hub. I just did it :-)

So it depends what is behind/inside the slot/adapter and how it is 
connected to the motherboard.

-o-

SD cards will wear out if you run an installed operating system from it 
because of repeated write operations on the same memory cells. So if you 
manage to boot from it, you should tweak it to avoid some of the wear. 
Add the mount option noatime in /etc/fstab. Do not locate any swap 
partition on the SD card. Turn off journaling. See this link,

https://help.ubuntu.com/community/Installation/UEFI-and-BIOS#Final_system_tweaks

An alternative is to use a persistent live system, and if there is 
enough RAM use the boot option toram. A persistent live system does not 
write as frequently to the drive as an installed system.

Best regards
Nio