Hi! I moved one of the SMR disks to another box with a 3.18.21 kernel.
I formatted and mounted like this: /opt/f2fs-tools/sbin/mkfs.f2fs -lTEST -s90 -t0 -a0 /dev/vg_test/test mount -t f2fs -onoatime,flush_merge,no_heap /dev/vg_test/test /mnt I then copied (tar | tar) 2.1TB of data to the disk, which took about 6 hours, which is about the read speed of this data set (so the speed was very good). When I came back after ~10 hours, I found a number of hung task messages in syslog, and when I entered sync, sync was consuming 100% system time. I took a snapshot of /sys/kernel/debug/f2fs/status before sync, and the values arfe "frozen", i.e. they didn't change. I was able to read from the mounted filesystem normally, and I was able to read and write the block device itself, so the disk is responsive. After ~1h in this state, I tried to umount, which made the filesystem mountpoint go away, but umount hangs, and /sys/kernel/debug/f2fs/status still doesn't change. This is the output of /sys/kernel/debug/f2fs/status: http://ue.tst.eu/d88ce0e21a7ca0fb74b1ecadfa475df0.txt I then deleted the device, but the echo 1 >/sys/block/sde/device/delete was also hanging. Here are /proc/.../stack outputs of sync, umount and bash(echo): sync: [<ffffffffffffffff>] 0xffffffffffffffff umount: [<ffffffff8139ba03>] call_rwsem_down_write_failed+0x13/0x20 [<ffffffff811e7ee6>] deactivate_super+0x46/0x70 [<ffffffff81204733>] cleanup_mnt+0x43/0x90 [<ffffffff812047d2>] __cleanup_mnt+0x12/0x20 [<ffffffff8108e8a4>] task_work_run+0xc4/0xe0 [<ffffffff81012fa7>] do_notify_resume+0x97/0xb0 [<ffffffff8178896f>] int_signal+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff bash (delete): [<ffffffff810d8917>] msleep+0x37/0x50 [<ffffffff8135d686>] __blk_drain_queue+0xa6/0x1a0 [<ffffffff8135da05>] blk_cleanup_queue+0x1b5/0x1c0 [<ffffffff8152082a>] __scsi_remove_device+0x5a/0xe0 [<ffffffff815208d6>] scsi_remove_device+0x26/0x40 [<ffffffff81520917>] sdev_store_delete+0x27/0x30 [<ffffffff814bf748>] dev_attr_store+0x18/0x30 [<ffffffff8125bc4d>] sysfs_kf_write+0x3d/0x50 [<ffffffff8125b154>] kernfs_fop_write+0xe4/0x160 [<ffffffff811e51a7>] vfs_write+0xb7/0x1f0 [<ffffffff811e5c26>] SyS_write+0x46/0xb0 [<ffffffff817886cd>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff After a forced reboot, I did a fsck, and got this, which looks good except for the "Wrong segment type" message, which hopefully is harmless. http://ue.tst.eu/4c750d2301a581cb07249d607aa0e6d0.txt After mounting, status was this (and was changing): http://ue.tst.eu/6462606ac3aa85bde0d6674365c86318.txt Note that 1.4TB of data are missing(!) This large amount of missing data was certainly unexpected. I assume f2fs stopped checkpointing earlier, and only after a checkpoint the data is safe, but being able to write 1.4TB of data without it ever reaching the disk is very unexpected behaviour for a filesystem (which normally loses about half a minute of data at most). Minor question, since the disk actually has 4K physical sectors, and fsck says sector size = 512, is there a way to teach f2fs that the physical sector size is actually 4k, or does this not matter because f2fs will do page-sized writes anyways? In any case, any insights would be appreciated. I will attwmpt to upgrade this box to linux 4.2.1 to see if that helps, but 3.18.x is the onl kernel known to work with smr drives without any issues. -- The choice of a Deliantra, the free code+content MORPG -----==- _GNU_ http://www.deliantra.net ----==-- _ generation ---==---(_)__ __ ____ __ Marc Lehmann --==---/ / _ \/ // /\ \/ / schm...@schmorp.de -=====/_/_//_/\_,_/ /_/\_\ ------------------------------------------------------------------------------ Monitor Your Dynamic Infrastructure at Any Scale With Datadog! Get real-time metrics from all of your servers, apps and tools in one place. SourceForge users - Click here to start your Free Trial of Datadog now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
