Snap failing to remove old core doesn't update and keeps spinnig the CPU

[Marco Trevisan (Treviño)]

Various issues here...

I noticed snapd was using CPU in my system... Once saw that I noticed that it was due to its impossibility to remove an old core during auto-refresh.

So, I had to abort the pending change myself or it was trying to redo this forever:

snap change 960
Status Spawn Ready Summary
Done today at 01:31 CEST today at 16:50 CEST Ensure prerequisites for "core" are available
Undone today at 01:31 CEST today at 16:50 CEST Download snap "core" (7396) from channel "stable"
Done today at 01:31 CEST today at 16:50 CEST Fetch and check assertions for snap "core" (7396)
Error today at 01:31 CEST today at 16:50 CEST Mount snap "core" (7396)
Undone today at 01:31 CEST today at 16:49 CEST Run pre-refresh hook of "core" snap if present
Undone today at 01:31 CEST today at 16:49 CEST Stop snap "core" services
Undone today at 01:31 CEST today at 16:49 CEST Remove aliases for snap "core"
Undone today at 01:31 CEST today at 16:49 CEST Make current revision for snap "core" unavailable
Undone today at 01:31 CEST today at 16:49 CEST Copy snap "core" data
Undone today at 01:31 CEST today at 16:49 CEST Setup snap "core" (7396) security profiles
Undone today at 01:31 CEST today at 16:48 CEST Make snap "core" (7396) available to the system
Undone today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "core"
Undone today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "core"
Undone today at 01:31 CEST today at 16:48 CEST Setup snap "core" aliases
Undone today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "core" snap if present
Undone today at 01:31 CEST today at 16:48 CEST Start snap "core" (7396) services
Done today at 01:31 CEST today at 16:50 CEST Remove data for snap "core" (7169)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "core" (7169) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "core" (7396) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "core" snap if present
Done today at 01:31 CEST today at 16:52 CEST Ensure prerequisites for "core18" are available
Undone today at 01:31 CEST today at 16:52 CEST Download snap "core18" (1098) from channel "stable"
Done today at 01:31 CEST today at 16:52 CEST Fetch and check assertions for snap "core18" (1098)
Error today at 01:31 CEST today at 16:52 CEST Mount snap "core18" (1098)
Undone today at 01:31 CEST today at 16:49 CEST Run pre-refresh hook of "core18" snap if present
Undone today at 01:31 CEST today at 16:49 CEST Stop snap "core18" services
Undone today at 01:31 CEST today at 16:49 CEST Remove aliases for snap "core18"
Undone today at 01:31 CEST today at 16:49 CEST Make current revision for snap "core18" unavailable
Undone today at 01:31 CEST today at 16:49 CEST Copy snap "core18" data
Undone today at 01:31 CEST today at 16:49 CEST Setup snap "core18" (1098) security profiles
Undone today at 01:31 CEST today at 16:48 CEST Make snap "core18" (1098) available to the system
Undone today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "core18"
Undone today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "core18"
Undone today at 01:31 CEST today at 16:48 CEST Setup snap "core18" aliases
Undone today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "core18" snap if present
Undone today at 01:31 CEST today at 16:48 CEST Start snap "core18" (1098) services
Done today at 01:31 CEST today at 16:52 CEST Clean up "core18" (1098) install
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "firefox" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "firefox" (262) from channel "beta"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "firefox" (262)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "firefox" (262)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "firefox" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "firefox" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "firefox"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "firefox" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "firefox" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "firefox" (262) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "firefox" (262) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "firefox"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "firefox"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "firefox" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "firefox" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "firefox" (262) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "firefox" (248)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "firefox" (248) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "firefox" (262) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "firefox" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "clion" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "clion" (82) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "clion" (82)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "clion" (82)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "clion" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "clion" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "clion"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "clion" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "clion" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "clion" (82) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "clion" (82) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "clion"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "clion"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "clion" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "clion" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "clion" (82) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "clion" (73)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "clion" (73) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "clion" (82) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "clion" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "opera" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "opera" (49) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "opera" (49)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "opera" (49)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "opera" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "opera" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "opera"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "opera" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "opera" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "opera" (49) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "opera" (49) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "opera"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "opera"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "opera" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "opera" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "opera" (49) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "opera" (44)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "opera" (44) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "opera" (49) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "opera" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "code" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "code" (14) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "code" (14)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "code" (14)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "code" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "code" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "code"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "code" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "code" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "code" (14) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "code" (14) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "code"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "code"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "code" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "code" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "code" (14) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "code" (11)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "code" (11) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "code" (14) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "code" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "go" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "go" (4301) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "go" (4301)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "go" (4301)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "go" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "go" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "go"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "go" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "go" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "go" (4301) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "go" (4301) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "go"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "go"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "go" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "go" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "go" (4301) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "go" (3947)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "go" (3947) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "go" (4301) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "go" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "gnome-3-26-1604" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "gnome-3-26-1604" (92) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "gnome-3-26-1604" (92)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "gnome-3-26-1604" (92)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "gnome-3-26-1604" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "gnome-3-26-1604" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "gnome-3-26-1604"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "gnome-3-26-1604" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "gnome-3-26-1604" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "gnome-3-26-1604" (92) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "gnome-3-26-1604" (92) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "gnome-3-26-1604"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "gnome-3-26-1604"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "gnome-3-26-1604" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "gnome-3-26-1604" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "gnome-3-26-1604" (92) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "gnome-3-26-1604" (88)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "gnome-3-26-1604" (88) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "gnome-3-26-1604" (92) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "gnome-3-26-1604" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "skype" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "skype" (86) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "skype" (86)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "skype" (86)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "skype" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "skype" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "skype"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "skype" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "skype" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "skype" (86) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "skype" (86) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "skype"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "skype"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "skype" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "skype" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "skype" (86) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "skype" (60)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "skype" (60) from the system
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "skype" (63)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "skype" (63) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "skype" (86) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "skype" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "gnome-3-28-1804" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "gnome-3-28-1804" (71) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "gnome-3-28-1804" (71)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "gnome-3-28-1804" (71)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "gnome-3-28-1804" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "gnome-3-28-1804" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "gnome-3-28-1804"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "gnome-3-28-1804" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "gnome-3-28-1804" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "gnome-3-28-1804" (71) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "gnome-3-28-1804" (71) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "gnome-3-28-1804"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "gnome-3-28-1804"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "gnome-3-28-1804" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "gnome-3-28-1804" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "gnome-3-28-1804" (71) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "gnome-3-28-1804" (63)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "gnome-3-28-1804" (63) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "gnome-3-28-1804" (71) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "gnome-3-28-1804" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "telegram-desktop" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "telegram-desktop" (911) from channel "edge"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "telegram-desktop" (911)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "telegram-desktop" (911)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "telegram-desktop" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "telegram-desktop" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "telegram-desktop"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "telegram-desktop" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "telegram-desktop" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "telegram-desktop" (911) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "telegram-desktop" (911) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "telegram-desktop"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "telegram-desktop"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "telegram-desktop" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "telegram-desktop" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "telegram-desktop" (911) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "telegram-desktop" (868)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "telegram-desktop" (868) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "telegram-desktop" (911) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "telegram-desktop" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Ensure prerequisites for "snapcraft" are available
Hold today at 01:31 CEST today at 16:48 CEST Download snap "snapcraft" (3308) from channel "stable"
Hold today at 01:31 CEST today at 16:48 CEST Fetch and check assertions for snap "snapcraft" (3308)
Hold today at 01:31 CEST today at 16:48 CEST Mount snap "snapcraft" (3308)
Hold today at 01:31 CEST today at 16:48 CEST Run pre-refresh hook of "snapcraft" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Stop snap "snapcraft" services
Hold today at 01:31 CEST today at 16:48 CEST Remove aliases for snap "snapcraft"
Hold today at 01:31 CEST today at 16:48 CEST Make current revision for snap "snapcraft" unavailable
Hold today at 01:31 CEST today at 16:48 CEST Copy snap "snapcraft" data
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "snapcraft" (3308) security profiles
Hold today at 01:31 CEST today at 16:48 CEST Make snap "snapcraft" (3308) available to the system
Hold today at 01:31 CEST today at 16:48 CEST Automatically connect eligible plugs and slots of snap "snapcraft"
Hold today at 01:31 CEST today at 16:48 CEST Set automatic aliases for snap "snapcraft"
Hold today at 01:31 CEST today at 16:48 CEST Setup snap "snapcraft" aliases
Hold today at 01:31 CEST today at 16:48 CEST Run post-refresh hook of "snapcraft" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Start snap "snapcraft" (3308) services
Hold today at 01:31 CEST today at 16:48 CEST Remove data for snap "snapcraft" (3210)
Hold today at 01:31 CEST today at 16:48 CEST Remove snap "snapcraft" (3210) from the system
Hold today at 01:31 CEST today at 16:48 CEST Clean up "snapcraft" (3308) install
Hold today at 01:31 CEST today at 16:48 CEST Run configure hook of "snapcraft" snap if present
Hold today at 01:31 CEST today at 16:48 CEST Consider re-refresh of "core18", "firefox", "opera", "skype", "gnome-3-26-1604", "gnome-3-28-1804", "telegram-desktop", "snapcraft", "core", "clion", "code", "go"

......................................................................
Mount snap "core" (7396)

2019-09-09T16:50:58+02:00 ERROR remove /snap/core/7396: device or resource busy

......................................................................
Make current revision for snap "core" unavailable

2019-09-09T16:49:11+02:00 INFO Requested daemon restart.

......................................................................
Make snap "core" (7396) available to the system

2019-09-09T01:31:51+02:00 INFO Requested daemon restart.

......................................................................
Automatically connect eligible plugs and slots of snap "core"

2019-09-09T01:31:51+02:00 INFO Waiting for restart...

......................................................................
Remove snap "core" (7169) from the system

2019-09-09T16:19:34+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:22:34+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:25:34+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:28:34+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:31:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:34:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:37:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:40:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:43:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
2019-09-09T16:46:35+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy

......................................................................
Mount snap "core18" (1098)

2019-09-09T16:52:14+02:00 ERROR [show --property=ActiveState snap-core18-1098.mount] failed with exit status 1: Failed to get properties: Connessione scaduta

---

Once I've killed all the snaps running on current core, that were using it (according to lsof), I've been running refresh myself:

snap refresh
Setup snap "core" (7396) security profiles -
Setup snap "core" (7396) security profiles \
Setup snap "core" (7396) security profiles |
2019-09-09T17:39:10+02:00 INFO Waiting for restart...
2019-09-09T17:39:13+02:00 ERROR cannot remove snap file "core", will retry in 3 mins: remove /snap/core/7169: device or resource busy
Remove snap "core" (7169) from the system -error: cannot perform the following tasks:
- Mount snap "core" (7396) (remove /snap/core/7396: device or resource busy)

[Zygmunt Krynicki (zyga)]

During further analysis of this issues I have some comments:

1) There's no mechanism in the state engine to prevent spinning of tasks. This is the direct cause of the CPU usage.

2) There's no mechanism in snapd to prevent removal of revisions that are in active use. While some of this this will become available once ongoing work on refresh-app-awareness lands, when we can at least analyse the processes and their resource usage, I wonder if there's something we can do short-term to improve the situation.

As a way to address 2) I've opened https://github.com/snapcore/snapd/pull/7433