IO errors on buster when restoring snapshot from previous run with --keep-snapshots

persistence.feature doesn’t pass at the moment because we lose the remote shell quite easily.

@product
Feature: Tails persistence
  As a Tails user
  I want to use Tails persistence feature

    Checkpoint: I have started Tails from DVD without network and stopped at Tails Greeter's login screen
      Given the network is unplugged
00:00:22.890929091: [log] CLICK on L(1023,384)@S(0)[0,0 1024x768]
      And I start the computer
00:01:11.097168628: calling as root: echo 'hello?'
00:01:11.097257235: [log]  TYPE " autotest_never_use_this_option blacklist=psmouse #ENTER."
00:01:11.246477905: call returned: [0, "hello?\n", ""]
00:01:11.249658224: calling as root: service tor status
00:01:11.334480810: call returned: [3, "● tor.service - Anonymizing overlay network for TCP (multi-instance-master)\n   Loaded: loaded (/lib/systemd/system/tor.service; disabled; vendor preset: enabled)\n   Active: inactive (dead)\n", ""]
00:01:11.334993101: opening file /etc/tor/torrc in 'append' mode
00:01:11.402447995: append complete
      And the computer boots Tails
00:01:28.964382109: calling as root: echo 'hello?'
00:01:29.024071217: call returned: [0, "hello?\n", ""]
00:01:29.747661330: calling as root: nmcli device show eth0
00:01:29.747755758: [log] CLICK on L(1023,384)@S(0)[0,0 1024x768]
  Scenario: Booting Tails from a USB drive with a disabled persistent partition                                                         # features/persistence.feature:6
    Given I have started Tails without network from a USB drive with a persistent partition and stopped at Tails Greeter's login screen # features/step_definitions/snapshots.rb:186
      execution expired (RemoteShell::Timeout)
      ./features/support/helpers/remote_shell.rb:34:in `readline'
      ./features/support/helpers/remote_shell.rb:34:in `block (2 levels) in communicate'
      ./features/support/helpers/remote_shell.rb:33:in `loop'
      ./features/support/helpers/remote_shell.rb:33:in `block in communicate'
      ./features/support/helpers/remote_shell.rb:30:in `communicate'
      ./features/support/helpers/remote_shell.rb:72:in `execute'
      ./features/support/helpers/remote_shell.rb:81:in `initialize'
      ./features/support/helpers/vm_helper.rb:433:in `new'
      ./features/support/helpers/vm_helper.rb:433:in `execute'
      ./features/support/helpers/vm_helper.rb:472:in `has_network?'
      ./features/step_definitions/common_steps.rb:33:in `post_snapshot_restore_hook'
      ./features/step_definitions/snapshots.rb:155:in `reach_checkpoint'
      ./features/step_definitions/snapshots.rb:153:in `reach_checkpoint'
      ./features/step_definitions/snapshots.rb:153:in `reach_checkpoint'
      ./features/step_definitions/snapshots.rb:153:in `reach_checkpoint'
      ./features/step_definitions/snapshots.rb:187:in `/^I\ have\ started\ Tails\ without\ network\ from\ a\ USB\ drive\ with\ a\ persistent\ partition\ and\ stopped\ at\ Tails\ Greeter's\ login\ screen$/'
      features/persistence.feature:7:in `Given I have started Tails without network from a USB drive with a persistent partition and stopped at Tails Greeter's login screen'

This will be debugged once we have results for other features in the test suite.

Parent Task: #16281 (closed)

Original created by @CyrilBrulebois on 16314 (Redmine)