Disk space should never bring a whole server down

girish

@marcusquinn when you say whole server down, do you mean that the dashboard is unreachable? Is the box code running systemctl status box and systemctl status nginx . If those two are up, things should be working.

AFAIK, there is no easy way to implement this feature. If a process starts writing into disk like crazy because of a bug or intentionally, then other processes which write to disk start crashing. Unless the app itself is resilient to this, it' tricky to implement (I guess one approach is to also disk sandbox all apps but that also AFAIK is not easy to do).

marcusquinn

@nebulon Thanks - tried all of that but all was OK.

@girish yeah, the Dashboard.

I think I've found an outlier symptom but not worked out how to solve yet.

If I login a fresh with Firefox at my.example.com I can get in again.

However, my main daily-driver "browser" for this is a WebCatalog (Electron) webapp.

So, here's the weird thing - I clear cookies and cache, I can get to the login screen. I login and just a blank https://my.brandlight.org/#/apps page, with nothing showing.

All other Cloudron servers and instances working fine.

Since it's working in Firefox now, I think it's safe to say no so urgent. My feeling is something went wrong when the disk filled up and somehow the browser now is all confused.

Anyway, lower priority - I'll keep digging and see if I can find the cause/cure with some luck...

marcusquinn

Ugh, nope, disk full again, whole server down. Makes me dislike weekends when this stuff happens.

No clue what to do but the post title remains valid - maybe Apps need diskspace limits because I'm caught between hard server resets, brief times of access, and then lockout again.

marcusquinn

Whatever 1000% CPU is doing, it's not showing a Cloudron Dashboard:

marcusquinn

# systemctl status box
● box.service - Cloudron Admin
   Loaded: loaded (/etc/systemd/system/box.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Sat 2021-03-06 23:22:48 UTC; 88ms ago
  Process: 311 ExecStart=/home/yellowtent/box/box.js (code=exited, status=1/FAILURE)
 Main PID: 311 (code=exited, status=1/FAILURE)

# systemctl status nginx
● nginx.service - nginx - high performance web server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/nginx.service.d
           └─cloudron.conf
   Active: active (running) since Sat 2021-03-06 23:09:24 UTC; 14min ago
     Docs: http://nginx.org/en/docs/
  Process: 1431 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=0/SUCCESS)
 Main PID: 1634 (nginx)
    Tasks: 17 (limit: 4915)
   CGroup: /system.slice/nginx.service
           ├─1634 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
           ├─1638 nginx: worker process
           ├─1639 nginx: worker process
           ├─1641 nginx: worker process
           ├─1642 nginx: worker process
           ├─1645 nginx: worker process
           ├─1646 nginx: worker process
           ├─1647 nginx: worker process
           ├─1648 nginx: worker process
           ├─1649 nginx: worker process
           ├─1650 nginx: worker process
           ├─1651 nginx: worker process
           ├─1652 nginx: worker process
           ├─1653 nginx: worker process
           ├─1654 nginx: worker process
           ├─1655 nginx: worker process
           └─1656 nginx: worker process

Mar 06 23:09:23 cloudron01 systemd[1]: Starting nginx - high performance web server...
Mar 06 23:09:24 cloudron01 systemd[1]: Started nginx - high performance web server.

Sorry, I have to work evenings and weekends, it's the only time I can concentrate on the deep work without all the emails & messages interruptions of the week days.

marcusquinn

# systemctl status unbound
● unbound.service - Unbound DNS Resolver
   Loaded: loaded (/etc/systemd/system/unbound.service; enabled; vendor preset: enabled)
   Active: active (running) since Sat 2021-03-06 23:26:38 UTC; 8s ago
 Main PID: 20802 (unbound)
    Tasks: 1 (limit: 4915)
   CGroup: /system.slice/unbound.service
           └─20802 /usr/sbin/unbound -d

Mar 06 23:26:38 cloudron01 systemd[1]: Started Unbound DNS Resolver.
Mar 06 23:26:38 cloudron01 unbound[20802]: [20802:0] notice: init module 0: subnet
Mar 06 23:26:38 cloudron01 unbound[20802]: [20802:0] notice: init module 1: validator
Mar 06 23:26:38 cloudron01 unbound[20802]: [20802:0] notice: init module 2: iterator
Mar 06 23:26:38 cloudron01 unbound[20802]: [20802:0] info: start of service (unbound 1.6.7).
Mar 06 23:26:39 cloudron01 unbound[20802]: [20802:0] error: could not fflush(/var/lib/unbound/root.key): No space left on device
Mar 06 23:26:39 cloudron01 unbound[20802]: [20802:0] error: could not fflush(/var/lib/unbound/root.key): No space left on device

marcusquinn

In just cannot get my head around how the disk can be allowed to fill to the point of a total system failure.

Slowdown, sure I understand - but it's a total fail and I can't see why this isn't preventable.

Is it really all one has to to bring a Cloudron down is load it up with data?

There's a bunch of Apps that allow for uploads, it really wouldn't take much effort to flood those with a few GB.

marcusquinn

@nebulon @girish App have Memory & CPU allocations - any reason they can't have disk- space allocations too?

I'd rather a single app hits a wall than an entire server.

It seems all one would have to do to bring a whole Cloudron down this way would be send a lot of email attachments to the point of disk saturation.

Maybe I'm wrong and it's something else - but feel free to delete this post and move to email if it's a reproducible risk.

girish

@marcusquinn said in Disk space should never bring a whole server down:

@nebulon @girish App have Memory & CPU allocations - any reason they can't have disk- space allocations too?

Yes, the memory & CPU allocations are features of the linux kernel cgroups. However, disk space allocation is not part of them.

I guess the issue atleast to handle right now is that for some reason disk space is full. Running docker image prune -a sometimes frees up some disk space. Can you try that? Alternately, if you drop me a mail on support , I can look into the server.

marcusquinn

@girish said in Disk space should never bring a whole server down:

docker image prune -a

OK, thanks, tried that: "Total reclaimed space: 816.4MB"

Still no respondio though. Have emailed support@ but 2am here and an early start, so back online in 8h or so, by which it'll be your 2am, and appreciate it's Saturday, so just grateful for pointers and hoping I might have some other requests for assistance waking up soon too.

robi

Can we add a disk space email alert, and event where after some critical threshold /tmp is cleaned up & docker images pruned by Cloudron.

Completely avoidable with a bit of this..

marcusquinn

I'm wondering if maybe Cloudron should have its own volume by default.

A quick search in the subject but kinda tired now:

girish

@marcusquinn Managed to bring it up by truncating many logs. Should be coming up in a bit, hold on.

marcusquinn

@girish Ahhhh - thank you kindly!

I have an unused 1TB volume mounted, although I'm not sure how much of the remaining free space is used in the Move function, as I guess that was killing it when I triggered to move the 16GB Jira App data to it?

d19dotca

@girish said in Disk space should never bring a whole server down:

Managed to bring it up by truncating many logs

Is this perhaps related to the issue I reported a little while back too, regarding the logrotate not running properly under certain circumstances?

marcusquinn

@d19dotca I remembered that mention, although fading brain never found or got to looking at that. I kinda think this situation is a bit too easy to get into and hard to get out of once its Terminal only.

marcusquinn

Going to trigger a move on Confluence to the mounted volume, it's 4.5GB with 7.5GB free space now on the main volume - so hopefully that's enough working space but I have to zzz, problems where I know I don't immediately know how to solve are kinda exhausting.

girish

@marcusquinn looks like things are back up! There is ~7GB left, so hopefully that should hold up for sometime.

girish

I am looking into some clues on what can be done to mitigate this, will report back. BTW, for the volume suggestion, this is possible. In fact, we used to do this very long ago with each app having it's own btrfs partition. Usually, people start with a simple VPS. This means that for this to work out of the box one has to create a loopback file system which is very slow. Also, when I logged in to your server, it was mysql that was down which was not happy with lack of disk.

I am wondering if the solution involves suggesting the user to make a specific kind of setup if they want to protect themselves against this kind of issue. That is totally doable (for example, suggest user to move platformdata and boxdata to a separate volume/disk post installation)

girish

@robi We actually have a disk space alert, in fact, it's there right now in the dashboard.

But the above is not super useful because it's just checking space in a cronjob. This cronjob is quite conservative because we don't want to keep spinning the disk too much. I am not aware of a way to get a "signal" from the server when disk space limits are hit. If a server fills up too fast between cron runs, the whole thing is useless...

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Disk space should never bring a whole server down