root partition full

[Robert24]

Thanks for your reply Schwarzer Kater. To be honest, all I want is not to have to think about partitions. This thing with the root directory being suddenly full to the point where I can't use deja dub backup is something that I would like to avoid in the future.
I'm not afraid of the terminal itself but I have no clue about the respective advantages of the different partitioning scheme. I don't even understand why the home and the root have to be on different partitions. But I will look at the link you shared and try to get an understanding of what is best for me.

[Robert24]

I read a bit about why it's good to have the root and home directory on different partitions and now I realize that there is maybe an option that I had not considered (sorry if that's absolutelt obvious 😅): could I not use my USB live key to simply extend the root partition with the space of the backup and swap partition? And reinstall Ubuntu 22.04 on this new root partition without wiping out my home partition? So my personal data would remain intact? I did a (manual) back up on an external hard drive, but maybe I don't need to copy back everything? I would prefer this because I'm a bit sorried that if I copy back my data frome the external HD to the newly formated /home partition, some repos github repo that I had cloned would not be well synced anymore (I won't go in the detail here but only part of my local repo is on GitHub).

[Schwarzer Kater]

I would strongly advise against using an USB stick permanently for any kind of system installation!
They are for example not designed for that purpose (e.g. they do not use S.M.A.R.T.), not durable enough concerning writes (unless you have perhaps an external "stick" case with an NVMe SSD…) and much slower than using an SATA SSD or an M.2 NVMe SSD mounted inside your computer.


There are many threads you can find in this forum about partitioning (mostly with ext4 - with btrfs you will at least need an additional EFI partition besides your root partition on your drive and there are certain things you have to be aware of with btrfs and swap files/subvolumes).
Here are just two examples - for btrfs-specific things best use the subforum mentioned above.

For a simple partitioning scheme (no extra /home or /swap) see: https://www.kubuntuforums.net/forum/...ual-partitions

For a little more complex one (extra /home) see: https://www.kubuntuforums.net/forum/...i-boot-working

I personally still prefer to have an additional swap partition as some kernel developers suggest…

[oshunluvr]

...I personally still prefer to have an additional swap partition as some kernel developers suggest…

Points to consider:

• Most users rarely if ever need swap any more. If they do, it need not follow the old formula for size.
• A swap file is easily adjusted in size or moved or removed.
• My reading says there's little or no performance difference between a swap file or partition.
• A swap partition is a permanent fixture that requires serious - and potentially dangerous - work to amend.

In this case, an inexperienced user just trying to get their system working - they are much better off without a swap partition. My recommendation here is to have a small swap file for those "just in case" moments and not a swap partition that will most likely go unused and just eat drive space for zero benefit. In my case and I suspect yours, we know whether or not swap will be needed and have the drive space to accommodate it. Our new friend Robert24 is a little short on drive space and not sure (which means likely not) if swap is needed or not. The only case that I recommend a swap partition anymore is someone who boots several distros and wants to share swap space across them. I too have a swap partition for this reason.


I think for Robert24: you should probably stay as simple as possible so you're not bogged down again trying to redo the install. My advice is to wipe the whole mess and re-install to a single partition. I also recommend BTRFS vs. EXT4 (any and every day). There are benefits including snapshot and backup features that are built into the file system rather than requiring external tools. No need to concern yourself with that now, just get your install up and running.

Since you're dual booting with windows you shouldn't need to add any other partitions as the EFI partition already exists.

[Robert24]

Schwarzer Kater Thank you for your answer! It seems I didn't phrase well what I had in mind: when I wrote

could I not use my USB live key to simply extend the root partition with the space of the backup and swap partition

I meant that I don't need to wipe out my /home partition. Maybe I can keep it and simply make the / partition bigger by adding to it the space retrieved from the backup and swap partitions deleted. Would it be doable? Would I even need to format the root partition at all and re-install Kubuntu 22.04?
I guess that I would have to stick with this ext4 format then, but if I don't count this root partition too full, I didn't have complaints with this format so far.
I will read the resources that you are pointing me too once I'm at home.

oshunluvr Thank you for your answer. Indeed, simplicity would be the best. As I mention, I would be glad I I can avoid formating my home partition but I'm ready to do it if there is no other choice. For the snapshot and backup features that you mentioned, I don't know them but I will read about it. So far deja dub back up has been good enough for me. Are there some inconvenient in having this BTRFS? Regarding this "swap file" is it something I woyld need to set up manually? Or would it be set up automatically in absence of a swap partition?

[claydoh]

Regarding this "swap file" is it something I woyld need to set up manually?

If you were to use one of the automatic install options, a swap file would be created automatically. If you do a manual partitioning, you would need to set this up yourself.

[Robert24]

Thanks for your reply claydoh . But if I use the automatic install option, what happens to my messy partitioning? Shouldn't I at least try to merge this backup partition into my root partition?

[claydoh]

Thanks for your reply claydoh . But if I use the automatic install option, what happens to my messy partitioning? Shouldn't I at least try to merge this backup partition into my root partition?

I am in agreement with oshunluvr that starting completely from scratch is probably the best path, though I have only lightly skimmed this thread. I also agree that swap isn't a dire necessity. But a clean slate will fix these issues here, and a fresh install will provide a swap file automatically.

[Robert24]

I get that most people recommend me a clean install, but I'm not sure how to proceed. When I select the "Guided option" it shows me a "Before and After" picture representing the state of the partition. It doesn't look great. It would create an additional partition made of around 50 GB taken from the current /home partition, without modifying the current / partition.
Now, looking at this thread:
https://www.kubuntuforums.net/forum/...i-boot-working
recommended by Schwarzer Kater , I realized that before any installation, I can chose the option "Try out Kubuntu" when I boot from the usb live key and modify the partitions at this point.

So, as an experiment, I shrunk my home partition which was next to the root partition and I then used the reclaim space to increase the root partition. After, this I could reboot my Kubuntu session and the problem seemed fixed. But I want to follow your advice and do a clean installation. For this, I guess that the first step would be to delete all existing partitions related to Kubuntu. It looks feasible except for the swap partition. This one doesn't seem possible to modify (even when using the live key and the "Try out Kubuntu") and it has a little lock icon. It's annoying because it is in between some partitions and so it splits the space in two. Any idea what might be the issue here?

[Robert24]

I'm attaching here a screen shot of my partitions (this one is taken from my actual current Kubuntu session (the one I will wipe out)). As mentioned in the previous message, only the /dev/sda7 is locked when I use the usb live key.

[GreyGeek]

Well, to each his own!

I do a LOT of experimenting with applications, installations, coding (Python in 14 different projects) and just plain old simple wild hairs. I use debs, tars, flatpaks and appimages. The last two types are easy to remove, and systemd makes removing rogue sockets, etc., easy to remove as well. Sometimes installing an application creates "dependencies" with existing libraries that didn't exist before and your app wants to take your entire desktop with it if you delete it. Before I began using BTRFS restoring my system could take several hours or even days and, on occasions, resulted in a complete reinstall to clear things up. I see this happening on this forum regularly. Someone posts a msg asking for help in fixing their broken system after they've spent two or three days, or longer, trying to restore it to a working condition.

Now I don't mess with any uninstalls. Before I start a new project or install the app de jour I create a snapshot of my system. When I am done playing around I rollback to the snapshot. Total rollback time: a second or two to move @ to @old and another few seconds to type "btrfs subvol snapshot /mnt/snapshots/@xyz /mnt/@" and then reboot. When I am booted back up I use "btrfs subvol delete -C /mnt/@old", and close the Konsole. (BTW, I merged my @home into @ and deleted the @home subvolume, so I have only one snapshot to contend with and don't have to coordinate a version of @ with a version of @home.)

Another thing I like about BTRFS is that it is auto tuning. The are only a few settings and the only parameter setting I've used is to convert a subvolume from ro to rw or back.

[Robert24]

Thanks for your reply GreyGeek. I would do this btrfs set up if I wasn't blocked by this indestructible swap partition. As soon as I'll know how to wipe it out, I'll try out your recommendation.

[oshunluvr]

I thought I had said this before, but to reiterate: ANY partition in use will be LOCKED to prevent destruction of a running operating system. 

Your LiveUSB session detected and mounted the SWAP partition. This is expected.

[Schwarzer Kater]

You could e.g. either
sudo swapoff /dev/sda7 in the Konsole terminal emulator (also see man swapoff) to temporarily disable it and modify it afterwards (and don't forget to modify your swap entry in /etc/fstab accordingly(!) - to disable it permanently comment out the swap line in /etc/fstab and reboot)
or
boot from a GParted live USB stick (https://gparted.org/download.php) to be able to modify all of your partitions (be careful with that and have a working backup of the drive's important data on a seperate drive!).

[Robert24]

Schwarzer Kater Thanks a lot for your answer. I used the first option and it worked. Now I deleted 4 partitions: root, home, swap, and backup. I started the re-installation of Kubuntu, and I'm at the Disk Setup stage. I chose the "manual" option (all others would delete my windows partition(s)). On top of the window, it's written "Prepare partitions" and one can indeed create new partitions. I have 224'547 MB of "free space" so I guess I will create two partitions, one with around 40GB (40'000 MB), with mount point "/" and one with all the rest, with mount point "/home".
I need to choose from a drop down menu "Use as:" and this seems to be the disk format. From what I understood, the two encouraged options are either "Ext4 journaling file system" or "btrfs journaling file system". I was thinking of going for the btrf option which many seem to encourage.
Am I missing something?
By the way I read this thread which was recommended:
https://www.kubuntuforums.net/forum/...-working/page2
but it confused me more than it helped me understand, I have to admit . The center of the discussion seems to be this "efi" partition, which I think I already have and do not intend on touching if not necessary.

Anyway, thanks again for your support and have a great week!

[oshunluvr]

Schwarzer Kater Thanks a lot for your answer. I used the first option and it worked. Now I deleted 4 partitions: root, home, swap, and backup. I started the re-installation of Kubuntu, and I'm at the Disk Setup stage. I chose the "manual" option (all others would delete my windows partition(s)). On top of the window, it's written "Prepare partitions" and one can indeed create new partitions. I have 224'547 MB of "free space" so I guess I will create two partitions, one with around 40GB (40'000 MB), with mount point "/" and one with all the rest, with mount point "/home".
I need to choose from a drop down menu "Use as:" and this seems to be the disk format. From what I understood, the two encouraged options are either "Ext4 journaling file system" or "btrfs journaling file system". I was thinking of going for the btrf option which many seem to encourage.
Am I missing something?
By the way I read this thread which was recommended:
https://www.kubuntuforums.net/forum/...-working/page2
but it confused me more than it helped me understand, I have to admit . The center of the discussion seems to be this "efi" partition, which I think I already have and do not intend on touching if not necessary.

Anyway, thanks again for your support and have a great week!

Again - a restatement: If you are going to use BTRFS, you do not need and should not have a separate /home partition. If you use EXT4 then you might want a /home partition. Other that that, all looks OK. If you mess with or delete the EFI partition, not only will Kubuntu not install but Windows will no longer boot.

In my opinion, you've already had to wipe and reinstall once because you had a root partition that was too small. Why once again potentially subject yourself to the same situation by partitioning and using EXT4 when you can have all your space as one partition? BTRFS will allow your root and home subvolumes to expand and contract as needed all without you doing anything. "Subvolumes" are with BTRFS uses instead of partitioning. The subvolumes all reside on a single partition and share the free space as needed. If you make a separate home partition then you've eliminated half the reason to use BTRFS in the first place.

To show you what I mean, here is the output of df on my system minus tempfs and other irrelevant things:

stuart@office:~$ df -h
Filesystem       Size  Used Avail Use% Mounted on
/dev/nvme0n1p3   500G  355G  138G  73% /
/dev/nvme0n1p3   500G  355G  138G  73% /subvol
/dev/nvme0n1p3   500G  355G  138G  73% /home
​

Notice all these mount points are on the same partition. All show the exact same amount of used and free space - because they are all on the same partition (file system). The /subvol mount is not a subvolume, it's the full partition itself. There is so much used space because there are other subvolumes on that file system that are not mounted and thus don't show up in df output. There other subvolumes are other bootable installations and a snapshots folder where I keep daily snapshots. Here's the contents of /subvol:

stuart@office:~$ ll /subvol
total 24K
drwxr-xr-x 1 root root  160 Aug  7 08:06  ./
drwxr-xr-x 1 root root  178 Jul 11 07:37  ../
-rwxr-xr-x 1 root root 4.3K Dec 14  2022  dailysnapshots*
drwxr-xr-x 1 root root  166 Dec 15  2022 '@grub'/
drwxr-xr-x 1 root root  178 Jul 11 07:37 '@KDEneon'/
drwxr-xr-x 1 root root   32 Jun 20 12:42 '@KDEneon_home'/
drwxr-xr-x 1 root root  190 Aug  3 11:14 '@Kubuntu2004'/
drwxr-xr-x 1 root root  704 Aug  7 07:38  snapshots/
drwxr-xr-x 1 root root  154 Aug  3 09:00 '@Ubuntu_Server_2204'/
​

My main distro is KDEneon. You can see here I have a separate home for that install: @KDEneon_home. The other installs - Kubuntu 20.04, and Ubuntu Server 22.04, do not have separate homes.

Ubuntu based BTRFS installs will use two subvolumes by default: @ for / and @home for /home. You will not see these unless you mount the file system the way I have. There's a ton of threads on this forum about various BTRFS uses and even a subsection for it. If you decide to use BTRFS you will have plenty of resources for information available.