Re: freezes during snapshot creation/deletion -- to be expected? (Was: Re: btrfs based backup?)

[Chris Murphy <lists@colorremedies.com>]

On Thu, Nov 21, 2019 at 3:39 PM Marc Joliet <marcec@gmx.de> wrote:

> On a side note, I am also really annoyed by the lockups caused by qgroups.  On
> my Gentoo systems (which use btrbk) I have it disabled for that reason, but I
> left it on on my openSUSE laptop (a Dell XPS 13 9360), which locks up for
> about 15-30 minutes while cleaning up snapshots a few times a week (usually
> after reboots or after "zypper dup").

15 seconds is not at all acceptable on a desktop system, 15 minutes is
atrocious. A computer that appears to hang for 15 seconds, it is
completely reasonable for ordinary users to consider has totally
faceplanted, will not recover, and to force power off. The
distribution really needs to do something about that kind of negative
user experience.

And by the way, I've recently done some unprivileged compilations of
webkitgtk, with default options that cause n cores +2 to be used,
eating all available RAM and swap, and quickly totally hanging the
system while swap thrashing and basically acting like a fork bomb. I'm
using Btrfs for the rootfs as well as user home for this compile, and
have done hundreds of forced power offs during these events and have
seen exactly zero corruptions or Btrfs complaints. So at least there's
that, however unscientific a sample that is.


-- 
Chris Murphy