Timeshift borked my system (LM19.1 Cinnamon)

[warpz0ne]

Linux Mint 19.1 Cinnamon
Kernels 5.0.0-20 / 4.18.0-25 / 4.18.0-20
~26GB / (root) partition
Separate /home partition

Recently I've been getting the occasional notification that my root partition was running out of space. My web browser has had memory leaks before that filled up RAM then most of the swap partition, so I mentally categorized this the same way. Thought it was a bug, shrugged, and rebooted. Things kept working...until today.

The notification said there was no disk space left for root. I opened Disk Usage Analyzer but it did not seem able to complete the analysis. I rebooted, got to the Mint login screen, entered my credentials, screen went black, then login screen reappeared as if nothing happened. Tried other kernels, no change. I tried Ctrl+Shift+F2 and was able to log in via terminal, but startx was not able to complete because it could not write some auth file to disk. It gave a whole screen's worth of errors.

Booted into a live DVD environment, and here is what Disk Usage Analyzer found:

Timeshift had filled up the entire root partition.

So I went in via said live session and deleted all snapshots to free up space. Then, after logging into Mint like normal, Timeshift had the following settings:

This is something I'm pretty sure I never messed with. Or I accepted default settings and went on my merry way.

Why is Timeshift allowed to completely fill up a partition, with presumably default settings? If I were an average user, with just Mint on my one computer, and no way to create Mint media, I'd be left without a working OS. I'm still a little concerned that some files may have been corrupted after having no free space to which they could write changes.

[gittiest personITW]

Unfortunately it does look like Timeshift was doing what it was told to do.
Also unfortunately the setting wasn't ideal for your system.

What is the reason you're using Timeshift for?
If it is because you like to tinker with your system then it might be better for it to back up to an external drive on demand.

[cliffcoggin]

That you chose to ignore warnings about running out of space is your fault, not Timeshift's. I suggest you either store snapshots elsewhere or reduce the number you save.

[warpz0ne]

Unfortunately it does look like Timeshift was doing what it was told to do.

Break the system?

What is the reason you're using Timeshift for?

It was shilled for pretty hard with the release of Mint 19/Tara.
https://linuxmint.com/rel_tara_cinnamon_whatsnew.php

In Linux Mint 19, the star of the show is Timeshift. Although it was introduced in Linux Mint 18.3 and backported to all Linux Mint releases, it is now at the center of Linux Mint's update strategy and communication.

Who am I to go against that? If it's at the center of Mint's update strategy, it's gotta be safe for users of all skill & experience levels, right?

That you chose to ignore warnings about running out of space is your fault, not Timeshift's. I suggest you either store snapshots elsewhere or reduce the number you save.

Put yourself in the shoes of an average user. Not an experienced Linux nerd, an average user. Linux Mint is known as one of the most user friendly distros for beginners, so you're going to get a lot of average users. You've got to design for that demographic.

A warning comes up saying "There is little disk space remaining on / partition" or similar. What are they to think? If you installed Linux Mint for your parents (to keep them safer from malware, etc.), and included Timeshift as a safety, because you can't always be there to do tech troubleshooting, what would they think about a message like this? What to do to solve it? How would they know that Timeshift was the culprit for low disk space? How would they begin to solve anything if they were no longer able to log in to the GUI?

Would it not make sense for there to be a setting within Timeshift, say... "Minimum Disk Space Buffer" for Timeshift to leave alone? In such a scenario, the user could set xGB to remain free on the drive, untouchable by Timeshift, so that Timeshift is disabled until the user frees up space. I mean, it says if there is >1GB free space available, Timeshift will continue to run, but what if the next backup is 1.2GB? 5GB? And this is not able to be modified by the user?

It could be worded like "Allow Timeshift to run until xGB free space remains for the selected snapshot partition."

Isn't it a more safe usage scenario for Timeshift to stop running, rather than the entire system, due to lack of space? Sounds like common sense to me.

[Moem]

Personally I feel that Timeshift is a valuable tool, but in order for it to be easy to use for any type of user (including newcomers) the interface needs to be made clearer. It's too easy to mess up with it.

[gittiest personITW]

Completely agree - the software could be improved upon. All software can be improved upon.
Have you made a suggestion to teejee software?

If I was king of the world, I'd make it so that Timeshift could only back up to a non-system partition, and there would be limits and everyone would have a spare hard drive to back up to. That along with a harem.

Timeshift has saved my butt so many times that I feel it should be defended pretty much unconditionally.

[gm10]

Put yourself in the shoes of an average user. Not an experienced Linux nerd, an average user.

For the average user the Linux Mint installer creates a single big partition so the issue does not happen until their entire disk if full. In your case the issue was home made by storing timeshift snapshots onto a tiny root partition.

[Moem]

Completely agree - the software could be improved upon. All software can be improved upon.
Have you made a suggestion to teejee software?

I would, if I had some concrete and constructive suggestions. 'Make it better' by itself doesn't really help.

[AndyMH]

Timeshift has saved my butt so many times that I feel it should be defended pretty much unconditionally

Completely agree and likewise. But if the default is to save into the root partition, then that is bad. I always setup timeshift to backup to a separate drive, but then I don't think I'm a newbie anymore

[trytip]

computers and programs are mindless machines. humans have to make decisions for them. been using Timeshift and restored quite a lot of hiccups, but never did it fill me drive because i'm in charge of backups not timeshift. although if you want to fix something, you'd should be posting this minor inconvenience at the developer issue page not here.

5 freaking backups a day? you didn't once think that was too much. first thing i always do in any application is disable scheduling. i make a backup when needed, like before updates or doing major installing.

and each month after i'm satisfied with the system, i delete all snapshots and start fresh.

[gm10]

5 freaking backups a day? you didn't once think that was too much. first thing i always do in any application is disable scheduling. i make a backup when needed, like before updates or doing major installing.

Same. There's no reason to create a scheduled snapshot when you're not changing anything with the system. I'm usually only using my Update Manager's functionality to create a snapshot right before updates, and only when it's updates I know could be problematic.

Still, in his case the amount of snapshots isn't really the problem, it's the too small partition he's storing them to.

[gittiest personITW]

Timeshift has saved my butt so many times that I feel it should be defended pretty much unconditionally

Completely agree and likewise. But if the default is to save into the root partition, then that is bad. I always setup timeshift to backup to a separate drive, but then I don't think I'm a newbie anymore

Up till a couple of weeks ago I had TS backing up a ridiculous amount of times per day - but I was still tinkering and screwing up.
Now it is a working system - no more tinkering for now on this system, so TS has been only doing boot and daily, the odd On Demand before a kernel update - just in case.
Gone from 100GB of TS files to about 50GB - which is fine as it is using a separate drive.

Re - improving the software - yes - it does need constructive ideas. I am ok with how it works and think its cheeky to go "I want ....." all the time.
If I thought I had good ideas I would contact Teejee.
The OP thinks that they have good ideas, so go for it.
All good.
Am a bit addicted to this forum all told.

[AndyMH]

but I was still tinkering and screwing up.

Been there, done it, and got the teeshirt - looking a bit frayed now

[yekim54]

5 freaking backups a day? you didn't once think that was too much.

I'm trying to understand why you think the OP was doing "5 freaking backups a day". I may be wrong, but the way I read his TimeShift schedule, he was doing one backup per day and keeping the 5 most recent backups on his disk.

[cliffcoggin]

5 freaking backups a day? you didn't once think that was too much.

I'm trying to understand why you think the OP was doing "5 freaking backups a day". I may be wrong, but the way I read his TimeShift schedule, he was doing one backup per day and keeping the 5 most recent backups on his disk.

A good point Yekim. Nevertheless it still totalled a mere 5 snapshots being retained. A trivial number if stored in a suitably sized location.

Personally my schedule is 3 daily, 2 weekly, and 2 monthly. That's probably excessive but as I have loads of storage I can't be bothered to change it.

[rjsrjs]

I put Timeshift backups on a 1 tb external USB HDD via on demand method. I don't use any Timeshift scheduled backup for the very reason you are experiencing. I only have a 180 GB SSD drive (Already down to 120 GB free space) and have to be careful what I put on it. Either cut down on your Timeshift schedule backups or don't use scheduling at all. Only problem with Timeshift is the drive you put your backups on have to be formatted in Linux format, Ext4, Ext3, Ext2 ETC. I use partitions of 100 MB formatted to Ext 4 to put my Timeshift backups on.
Good luck.

[AndyMH]

On all my laptops and desktop I've got timeshift (and backintime) running automatically to a separate internal (but removable) HDD (cheap - 5400rpm), sizes vary from 500G to 2TB.

[cliffcoggin]

It could be worded like "Allow Timeshift to run until xGB free space remains for the selected snapshot partition."

But that's precisely what is displayed. The bottom line of your screenshot reads to the effect that snapshots will be created if there is more than 1GB of space.

[Flemur]

This is something I'm pretty sure I never messed with.

The filling-disk-with-backups-then-it-wont-boot problem has been mentioned here fairly frequently. Can't you change the settings which define where it saves backups? (I use grsync).

[warpz0ne]

I have held off on replying until I was able to do some Timeshift testing in a virtual machine. Remember when I said the following?

This is something I'm pretty sure I never messed with. Or I accepted default settings and went on my merry way.

My memory was correct. On first run, Timeshift shows a wizard (you can access it again later) with the following initial page:

If you press [Finish], all the settings that I showed before are accepted. That is, it defaults Timeshift backups saving to the root partition and 5x backups total, daily frequency. As a user, I assumed that since Timeshift was now an essential part of Linux Mint's update process, I could trust the default settings without further consideration. Keep in mind, when you click that wizard's [Finish] button, it gives you a big green ☑ "Timeshift is active" indicator—i.e., everything's good! And it does NOT show the save location or frequency unless you actively seek it out in settings.

I put Timeshift backups on a 1 tb external USB HDD via on demand method.

I thought I'd try this, because I do have a spare USB storage device. So I formatted it ext4, called it Timeshift, and promptly backed up my laptop's Mint. Then, I went over to my desktop to back up that Mint system, only to find that Timeshift was showing the laptop snapshot. It apparently does not distinguish between different systems/hostnames, at least with rsync, no idea regarding btrfs. Timeshift also states that it saves to /timeshift and this is not user configurable.

Code: Select all

•Snapshots are saved to /timeshift on selected partition. Other locations are not supported.

So even if I wanted to, I could not make separate directories for /desktop and /laptop snapshots on the same storage device. How cumbersome!

I did not dare even come close to the [Restore] button, because I didn't want to hose my system (again) by restoring the laptop partition to the desktop. Hence, virtual machine testing. After selecting the laptop snapshot in the virtual machine, which is not distinguished in any obvious way in the Timeshift UI from any other machine's backup other than date/time and system version (both laptop and desktop are 19.1 Tessa), I went thru the restore process, partly shown here:

It then says

Code: Select all

Data will be modified on following devices:
Device      Mount
---------   ------
/dev/sda1   /

Please save your work and close all applications.
System will reboot after files are restored.

Along with a disclaimer about no warranty, no responsibility for a FUBAR'd system, etc. Standard CYA fare.

Click next, and it was off to the races, restoring a Timeshift snapshot from my laptop, to a Mint virtual machine. Never a warning about "the snapshot system's hostname does not match the hostname of the target system" or anything similar. What this means is, if you use Timeshift to backup more than one system on the same external storage device, and those systems are the same version of Linux (in my case, 19.1 Tessa), there is no distinguishing between the snapshots and you are very likely to screw up your system when restoring a snapshot. Like this, the first reboot of the virtual machine post-Timeshift restore:

Oopsie.

I'm guessing the virtual machine screwup mainly has to do with legacy vs. EFI boot, as the laptop Mint is EFI. I tried the restore a second time as a test, selecting the "Update initramfs" option, but no dice. Still FUBAR. Also, thank God for virtual machines. Seriously.

For the average user the Linux Mint installer creates a single big partition so the issue does not happen until their entire disk if full. In your case the issue was home made by storing timeshift snapshots onto a tiny root partition.

This is a fair point, but I also will note that many new users follow guides on "How to install Linux" and many of these same guides recommend a separate, only-as-large-as-necessary root partition (~20GB) and a separate /home partition. When I started out, I followed a guide like that.

Have you made a suggestion to teejee software?

At first I was unable to find any contact email address, only social media, which I don't do. Further investigation revealed a PayPal donation email. So I will be sending a friendly email to teejee and directing him to my concerns in this thread.