So I have been seeing an issue with an intermittent boot hang on my x86 KVM VM with the latest linux-next and have bisected it down to the following commit: 1efa3bb79d3de8ca1b7f6770313a1fc0bebe25c7 is the first bad commit commit 1efa3bb79d3de8ca1b7f6770313a1fc0bebe25c7 Author: Mike Snitzer <snitzer@xxxxxxxxxx> Date: Fri Feb 22 11:23:01 2019 -0500 dm: must allocate dm_noclone for stacked noclone devices Otherwise various lvm2 testsuite tests fail because the lower layers of the stacked noclone device aren't updated to allocate a new 'struct dm_clone' that reflects the upper layer bio that was issued to it. Fixes: 97a89458020b38 ("dm: improve noclone bio support") Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> What I am seeing is in about 3 out of 4 boots the startup just hangs at the filesystem check stage with the following message: [ OK ] Reached target Local File Systems (Pre). Starting File System Check on /dev/…127-ad57-426f-bb45-363950544c0c... [ **] (1 of 2) A start job is running for…n on device 252:2 (19s / no limit) I did some googling and it looks like a similar issue has been reported for s390. Based on the request for data there I have the following info: [root@localhost ~]# dmsetup ls --tree fedora-swap (253:1) └─ (252:2) fedora-root (253:0) └─ (252:2) [root@localhost ~]# dmsetup table fedora-swap: 0 4194304 linear 252:2 2048 fedora-root: 0 31457280 linear 252:2 4196352 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel