Re: zpool/zfs-commands hang; ZFS filesystem/ZVOLs still running.

On Fri, Jun 17, 2022 at 10:46 AM Eric Borisch <eborisch@gmail.com> wrote:
>
> Good morning,
>
> I have a 13.1 system where twice now (required hard restart last time
> to resolve) since upgrading from 12.x I have had zfs/zpool-command
> operations start to hang indefinitely, while the underlying pools are
> still actively running/processing data via both filesystem and device
> interfaces.

I went back to some data I captured during the first instance, and it
also had a zfs destroy and zfs send in perpetual D-state:

11076  -  D         0:00.01 zfs destroy -d
kspace/users/eborisch@zfs-auto-snap_frequent-2022-06-13-08h15
16564  -  D         0:22.82 /sbin/zfs send -L -RI @MARK-mr-dewey
kspace@NEW-mr-dewey

11076 190929 zfs                 -
    mi_switch
    _sleep
    rms_wlock
    zfs_umount
    dounmount
    zfsctl_snapshot_unmount
    zfs_ioc_destroy_snaps
    zfsdev_ioctl_common
    zfsdev_ioctl
    devfs_ioctl
    vn_ioctl
    devfs_ioctl_f
    kern_ioctl
    sys_ioctl
    amd64_syscall
    fast_syscall_common
16564 190128 zfs                 -
    mi_switch
    _sleep
    rms_wlock
    zfs_umount
    dounmount
    zfsctl_snapshot_unmount
    dsl_dataset_user_release_impl
    dsl_dataset_user_release_onexit
    zfs_onexit_destroy
    zfsdev_close
    devfs_fpdrop
    devfs_close_f
    _fdrop
    closef
    closefp
    amd64_syscall
    fast_syscall_common

Note the particular @MARK- and @NEW- snapshots are different now, as
they are constantly destroyed/renamed during successful backup cycles,
which have occurred between these two events.

Thanks,
  - Eric