Score:1

Why can my system not find the /cow file mounted on root?

cg flag

I am running Lubuntu on a Windows system. It was set up using Oracle's Virtual Box. After two or three quite small installations, I was getting Write errors claiming the disk was full but since I have allocated 100GB to the VM I knew something fishy was going on. The following seems to show that there is a /cow filesystem mounted on root, and also that it is tiny, which is obviously the issue.

enter image description here

but when I try to deal with this issue, for example by running fdisk /cow I am told that no such file or directory exists. I really don't understand this and can't find much in the way of explanation already online, so I'm hoping someone can tell me why it is mounted on root yet doesn't exist.

guiverc avatar
cn flag
Your system isn't installed it looks like; thus the use of COW (Copy On Write). The *live* media is intended to *test* out the system and not be used in real-life situations (*you install for that purpose*) as COW can exceed the space allocated during boot. The COW exists in RAM and not on disk (*though in unix/posix terms everything is a file as the directory shows*) which is why `fdisk` can't run on it. I suggest installing the system properly to avoid the use of *live* media & thus avoiding endless CopyOnWrite, ie. all changes get saved by replacing data instead of copies added to a stack
Bodo avatar
pt flag
Please [edit] your question and add details: How exactly did you set up the VM and its virtual disks/media to run Lubuntu?
BigBaller avatar
cg flag
@guiverc I believe you are correct, your explanation makes a lot of sense, thanks for the help! Installing now, but I'm pretty sure that will solve the issue.
BigBaller avatar
cg flag
@guiverc, just to confirm, this has completely solved my issue. Apologies for the waste of time, not sure how I overlooked actually installing correctly, as the live medium does in fact suggest installation when you start it up. At least maybe someone else will benefit from this now it's here.
guiverc avatar
cn flag
We all learn ! (*if only some of didn't forget so much of what we learn...*) Some refer to the *write* of ISO to installation media as a *burn* as it's not an install (*but I can see how newer users could see it as installed*). You got there, and that's what matters so well done !
Score:2
cn flag

Your system isn't installed it looks like; thus the use of COW (Copy On Write).

The live media is intended to test out the system and not be used in real-life situations (you install for that purpose) as COW can exceed the space allocated [for it in RAM] during boot. The COW exists in RAM and not on disk (though in unix/posix terms everything is a file as the directory shows) which is why fdisk can't run on it.

I suggest[ed] installing the system properly to avoid the use of live media & thus avoiding endless CopyOnWrite, ie. all changes get saved by replacing data instead of copies added to a stack (the stack eventually fills and needs reboot).

Live systems are very useful; but they have their limits.

guiverc avatar
cn flag
answer mostly copy/paste from prior comment(s).. *Minor editing too that hopefully makes it a little clearer*
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