Hi Darrick, You're using it correctly and have found a bug, thanks! This patch fixes it: https://github.com/jthornber/linux-2.6/commit/6bbc70ab77ab828f1fecd8a3f4776b344eedef24 This is the test scenario I use (tweaked to catch your issue). def wait_for_all_clean(cache) cache.event_tracker.wait(cache) do |cache| status = CacheStatus.new(cache) STDERR.puts "#{status.nr_dirty} dirty blocks" status.nr_dirty == 0 end end def test_cleaner_policy with_standard_cache(:format => true) do |cache| git_prepare(cache, :ext4) cache.pause do table = cache.active_table table.targets[0].args[5] = 'cleaner' cache.load(table) end wait_for_all_clean(cache) cache.pause do table = cache.active_table table.targets[0].args[5] = 'mq' cache.load(table) end status = CacheStatus.new(cache) assert_equal(0, status.nr_dirty) end # We should be able to use the origin directly now with_standard_linear do |origin| fs = FS::file_system(:ext4, origin) fs.with_mount('./kernel_builds', :discard => true) do # triggers fsck end end end -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel