fixing a ten-year-old notebook computer for $5

I have, since late 2013, written on this blog about turning a Samsung R580 notebook into a personal Linux machine running Ubuntu. I won’t link, just search for Samsung and/or R580 to pick up the majority of the posts. The machine was originally purchased for my oldest daughter from Office Depot, and it came installed with Windows 7 Home Premium, or so the sticker on the bottom says. One day the Windows installation just seemed to eat itself up (probably due to a virus; my oldest wasn’t too careful in those days). I bought her a new one and put the R580 on the shelf for about six months. Then in late 2013 I pulled it down and for the hell of it installed Ubuntu 13.10 over Windows 7. And I haven’t looked back.

Not only have I kept it running Ubuntu since 2013, but I’ve also upgraded the hardware over the years, replacing the HDD with a 1TB Samsung Evo SDD when they got cheap enough and doubling the DRAM from 4GiB to 8GiB. It has done yeoman duty these past seven years. It was the first, and primary, Linux development platform, especially in support of my initial Raspberry Pi setup and support efforts.

All that changed over the past year as the R580 began to erratically fail. At first I thought the R580 was finally reaching end-of-life. But I discovered that the problem was with the power connector. It would fail to electrically connect with the power brick, and thus, the battery would run down and it would shut down. It got so bad that it went into the bag almost permanently around Halloween of last year. I wondered at the time if I would buy a replacement from System76.

Well, retirement and a fixed income can put the kibosh on grandiose plans that call for lots of cash. So I went looking around on YouTube to find any tutorials on fixing that R580 problem, found one I understood, ordered the replacement part from Amazon, and then spent two hours one evening disassembling this beast, replacing the power connector, and putting it all back together again. I had no leftover parts and it looks like I plugged every cable back in properly, because it came back on the first time I checked it out.

I have every intention of trying to update the R580 to Ubuntu 20.04 LTS, and leave it there, just like I’ve left it on 18.04 LTS. It does all I need, it’s speedy enough, and $5 is a damn sight cheaper than $100s for a new machine. Yes, retirement on a fixed income turns you into a cheap old bastard real fast.

ugly surprises with raspbian buster and external file systems

A while back I wrote about adding an SSD to a Raspberry Pi 4 and modifying /etc/fstab so that it would automatically mount when it booted. This is different than having it automount through /media/pi, since that type of automount only occurs after the OS is fully up and then scans for attached devices, such as those on USB. For nearly all use cases you can’t tell one from the other. But for those very few use cases where you need the kernel to mount the attached storage device before the rest of the system comes up, you need to define it in /etc/fstab.

That wasn’t a problem with Raspbian Buster up until just recently. Before that time, I had an entry for my SSD in fstab that started out like this:

/dev/sda1 ...

It worked just fine, until one day after a recent update that included the kernel, it didn’t. No warning that this was going to happen, none at all. After the update and subsequent reboot, the Raspberry Pi refused to boot, and instead dropped me into a prompt waiting for me to log in as root to fix the problem. Oh, wait, root is disabled by default in Raspian, so that just put me in an endless boot loop.

It took two attempts rebuilding a minimal boot micro SDXC before I finally figured out what was happening. Fortunately, that second micro SDXC card was a new one with a minimal Raspbian system, so it didn’t take too much effort to see that adding the entry to /dev/sda1 was causing it to fail to boot. Fortunately for me I have other Linux systems (my ten-year-old Samsung R580 running Ubuntu 18.04.04 came to the rescue) that allowed me to mount both micro SDXC cards, edit fstab and remove the entries. Once removed, both micro SDXC cards booted just fine in the Raspberry Pi 4.

Once I got back in I enabled root with ‘sudo passwd root’ and gave it a password. Now, if I have a problem where a Raspbian boot failure wants to dump me into the root account in single user mode, I can actually log in at that point.

The other problem was getting the USB SSD to mount. Here’s what I did to fix that. But first, a tiny bit of background.

The kernel in Raspbian buster uses what’s now known as a PARTUUID to identify a storage device instead of the old school device name in /dev. To find out what that PARTUUID is, you have to run this command at the command line in a terminal window:

pi@rpi4-4-01:~ $ sudo blkid
/dev/mmcblk0p1: LABEL_FATBOOT="boot" LABEL="boot" UUID="69D5-9B27" TYPE="vfat" PARTUUID="d9b3f436-01"
/dev/mmcblk0p2: LABEL="rootfs" UUID="24eaa08b-10f2-49e0-8283-359f7eb1a0b6" TYPE="ext4" PARTUUID="d9b3f436-02"
/dev/sda1: LABEL="SSD" UUID="ad89d540-a007-4d0a-887b-0b0dbefe3e8e" TYPE="ext4" PARTUUID="937a0120-01"
/dev/mmcblk0: PTUUID="d9b3f436" PTTYPE="dos"

Since I already know the label on my SSD is “SSD” it’s quickly identifiable in blkid’s output. Copy the PARTUUID at the end of the entry, and use that in the fstab entry for the drive, like so:

PARTUUID=937a0120-01 /ssd ext4 defaults,auto,users,rw,nofail,x-systemd.device-timeout=30 0 0

Note that the quotes are not added to the entry. Also note all the flags I use, especially the shortened timeout (systemd.device-timeout=30) to shorten the wait during boot in case the SSD isn’t plugged in. The default is 90 seconds.

The primary reason I want the SSD mounted is because that’s where I put swap. In /etc/dphys-swapfile I add the following line:

# where we want the swapfile to be, this is the default

I want my swap on the SSD because testing has shown the SSD is an order of magnitude faster than the boot micro SDXC. I use the Raspberry Pi 4’s as development and native build machines, rather than set up an emulation and cross-compile tool chain on my Mac. Believe it or not, it’s a lot simpler the way I have it set up. This is a decent compromise that doesn’t require me to put the entire OS on the SSD and then configure the Raspberry Pi to boot off the SSD. There are some significant problems with that, such as the Rasberry Pi 4 wasn’t set up to do that for quite some time after its release, and the fact that once configured that way, you can’t go back. So I put swap on the SSD, then cd onto a work area on the SSD and develop and build away.

This all gets back to the bigger question: why did this change, and when did it change? I use the same type of setup, and the same SSD, on the Jetson Nano, and it’s running a tweaked version of Ubuntu 18.04.04, complete with the Ubuntu graphical desktop. The fstab entry for that is the regular device entry, /dev/sda1.

Oh well. I just keep reminding myself that this is just a hobby, and I’m retired.