Boot failure

[steve7233]

I was using Kubuntu yesterday and everything worked. This morning I can't get Kubuntu to finish booting. It starts to load but fails before the desktop. Blank screen except for first line: [ 1.874652] and the second line has! a static under score, probably a cursor. Can any one suggest something? I did have to shrink a partition to create a swap partition to play Cities Skylines I. CS II launches October 24, 2023! 😃 CS I, has a native Linux version! I never thought I would need a swap partition just to play a game. No mods or assets just the official DLC!

[Schwarzer Kater]

You did not tell us much about your hardware or e.g. if there was something updated yesterday before you switched off your computer…
Nvidia graphics card?

You seem to have modified your partitions. What did you do exactly? Did the UUIDs change? Did you change something in /etc/fstab?

[steve7233]

You did not tell us much about your hardware or e.g. if there was something updated yesterday before you switched off your computer…
Nvidia graphics card?

You seem to have modified your partitions. What did you do exactly? Did the UUIDs change? Did you change something in /etc/fstab?

I told you I created a swap partition to play Cities Skylines. Looks pike you failed to read everything. I seem to have got it fixed enough to get the Kubuntu desktop to come up. I can't get one of my Steam partitions to mount.

[steve7233]

It looks like the Grub recovery program doesn't understand the Logitech unifying receiver. I can't reliably use the recovery program as it literally takes 500 or more tries just to get fstab loaded into pico! Is there a way to add a driver to the rescue program? I don't have a wired keyboard to try. I can REM out the mount command so I can boot and then figure out what is wrong with the mount syntax.

[steve7233]

I found another keyboard but it has problems so it looks like GRUB doesn't work with wireless keyboards. Looks like my computer may be down for a few days because GRUB hasn't been update to use wireless keyboards or none that I have. Does anyone know if any wireless keyboards work with GRUB's emergency tool?

[steve7233]

I got one of my partitions back. It turned out the power connector had fallen off the SSD card. It seems my Emojo keyboard Firefox extension doesn't work on these forums. Strange it works almost everywhere. Ok. I just searched and found this site has a button for its own emojis. Anyway, I discovered that the UUID reported in KDE partition manager properties doesn't seem to work. I had to use the old method like /dev/sda1.

[jlittle]

I got one of my partitions back. It turned out the power connector had fallen off the SSD card. It seems my Emojo keyboard Firefox extension doesn't work on these forums. Strange it works almost everywhere. Ok. I just searched and found this site has a button for its own emojis.

As well as the site's own emojis, those in Unicode work, provided your browser uses a font that has them. For example:

☸♈ 🌚🌝🌴🍄🐲😀🙆

[jlittle]

I discovered that the UUID reported in KDE partition manager properties doesn't seem to work. I had to use the old method like /dev/sda1.

An alternative, that IMO is much less error-prone, is to apply and use labels. For example, this laptop's /etc/fstab has:

LABEL=lily2  /mnt/lily        ext4  noatime                0 2

A typical example of what can go wrong with UUIDs is found on this laptop. sudo blkid reports:

/dev/sda1: LABEL="lily2" UUID="6af85b5d-97e5-4391-b2e0-d3cccd3e491c" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="3b71e4d2-c7ca-b84f-939d-596bc244d1b0"
/dev/sda3: LABEL="lilybu" UUID="6af85b5d-97e5-4391-b2e0-d3cccd3e491c" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="b077f2a5-6129-4027-b728-834015ace851"

Note the UUIDs are the same, though the PARTUUIDs are different. I've forgotten what I did, but "lilybu" looks like a backup I made of "lily" when I resized it at some point. But because the /etc/fstab and my grub configuration use the labels, there's been no problems.

[steve7233]

An alternative, that IMO is much less error-prone, is to apply and use labels. For example, this laptop's /etc/fstab has:

LABEL=lily2 /mnt/lily ext4 noatime 0 2

A typical example of what can go wrong with UUIDs is found on this laptop. sudo blkid reports:

/dev/sda1: LABEL="lily2" UUID="6af85b5d-97e5-4391-b2e0-d3cccd3e491c" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="3b71e4d2-c7ca-b84f-939d-596bc244d1b0"
/dev/sda3: LABEL="lilybu" UUID="6af85b5d-97e5-4391-b2e0-d3cccd3e491c" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="b077f2a5-6129-4027-b728-834015ace851"

Note the UUIDs are the same, though the PARTUUIDs are different. I've forgotten what I did, but "lilybu" looks like a backup I made of "lily" when I resized it at some point. But because the /etc/fstab and my grub configuration use the labels, there's been no problems.

Thanks. I will look at this tomorrow.

[steve7233]

I tried mounting /not_steam using partUUID but it failed. I suspect I don't understand the syntax. I used rescue mode to boot without that mount and remarked -REM -, it out so I could reboot without the partition being mounted until I solve the problem.

[oshunluvr]

REM is not the way to skip a line in bash syntax. Use # just like in the comments above the mount lines.

[steve7233]

REM is not the way to skip a line in bash syntax. Use # just like in the comments above the mount lines.

I have been using that old Linux command for decades. It works just fine for skipping lines. The pound or hashtag symbol or whatever they are calling it these days is not the only way.

[steve7233]

It seems BTRFS subpartitions are a bit different when mounting using UUIDs. https://unix.stackexchange.com/quest...edirect=1&lq=1

[claydoh]

I have been using that old Linux command for decades. It works just fine for skipping lines. The pound or hashtag symbol or whatever they are calling it these days is not the only way.

REM is most definitely not a 'linux command'.
For an fstab, and other similar text config files, as well as bash, python etc, using 'REM" does NOT comment the line out whatsoever. You can see it in your text editor - note that the lines with a hash are in grey? This is a clear indication that the line is a comment. Note your lines are NOT grey.

If you were look through your logs, you will see that those lines produce an error or warning somewhere, instead of ignoring those lines.

[jlittle]

It seems BTRFS subpartitions are a bit different when mounting using UUIDs. https://unix.stackexchange.com/quest...edirect=1&lq=1

One or more of the posters in that stack exchange thread are confused about the use of UUIDs. The UUIDs listed with sudo btrfs subvolume list <whatever> are not used to mount subvolumes; they are used for other purposes, at least for checking parents for send/receive.

To mount a subvolume, the UUID of the whole filesystem is used, and the subvolume specified with subvol= or subvolid= options. This means all the subvolumes in a btrfs use the same UUID for mounting purposes. For example, on this system

$ findmnt --real -o target,source,uuid
TARGET               SOURCE                       UUID
/                    /dev/nvme0n1p3[/@r]          2d458e9e-4bdc-4ffa-acbe-14fb2c47acf2
├─/run/user/1000/doc portal
├─/.snapshots        /dev/nvme0n1p3[/@snapshots]  2d458e9e-4bdc-4ffa-acbe-14fb2c47acf2
├─/t                 /dev/nvme0n1p3               2d458e9e-4bdc-4ffa-acbe-14fb2c47acf2
└─/home              /dev/nvme0n1p3[/@h]          2d458e9e-4bdc-4ffa-acbe-14fb2c47acf2
└─/home/.snapshots   /dev/nvme0n1p3[/@hsnapshots] 2d458e9e-4bdc-4ffa-acbe-14fb2c47acf2

UUIDs are universally unique IDs used all over the place in computer systems. They are used for several purposes in a btrfs. It's easy to confuse one use with another.