On Wed, Jan 20, 2016 at 3:29 PM, Roman Mamedov <rm@xxxxxxxxxxx> wrote: > Hello, > > To reproduce... > > *) in one terminal window: > > btrfs sub create test > chattr +C test > cd test/ > while true; do dd if=/dev/zero of=zerofile bs=1M count=1024; sync; done > > *) in another terminal window start repeatedly snapshotting 'test', at random > 1-3-5 second intervals: > > mkdir snaps > btrfs sub snap test snaps/test-`date +%Y-%m-%dT%H:%M:%S` > > The 'dd' output of first window then looks like this for me: > > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 0.49982 s, 2.1 GB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 0.541291 s, 2.0 GB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 4.88021 s, 220 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 4.56427 s, 235 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 0.530991 s, 2.0 GB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 5.68497 s, 189 MB/s > dd: writing `zerofile': No space left on device > 1+0 records in > 0+0 records out > 0 bytes (0 B) copied, 0.000591943 s, 0.0 kB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 4.25015 s, 253 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 4.66459 s, 230 MB/s > dd: writing `zerofile': No space left on device > 1015+0 records in > 1014+0 records out > 1063489536 bytes (1.1 GB) copied, 3.0433 s, 349 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 4.24264 s, 253 MB/s > dd: writing `zerofile': No space left on device > 1+0 records in > 0+0 records out > 0 bytes (0 B) copied, 0.000647234 s, 0.0 kB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 3.56673 s, 301 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 3.71281 s, 289 MB/s > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 0.551317 s, 1.9 GB/s > ^C > ----- > > This also causes my KVM VMs to fail with a high probability during > snapshotting of their backing subvolume (as described in the previous thread). Try this: https://patchwork.kernel.org/patch/7967161/ (It's not a regression in 4.4 however, it has been there for a long time) > > -- > With respect, > Roman -- Filipe David Manana, "Reasonable men adapt themselves to the world. Unreasonable men adapt the world to themselves. That's why all progress depends on unreasonable men." -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
