kern/141010: "zfs scrub" fails when backed by files in UFS2

Gerald Gutierrez gerald.gutierrez at
Mon Nov 30 01:50:01 UTC 2009

>Number:         141010
>Category:       kern
>Synopsis:       "zfs scrub" fails when backed by files in UFS2
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Nov 30 01:50:00 UTC 2009
>Originator:     Gerald Gutierrez
>Release:        8.0-RELEASE
FreeBSD 8.0-RELEASE Freebsd 8.0-RELEASE #0: Sat Nov 21 15:02:08 UTC 2009 root at amd64

"zfs scrub" causes kernel panic with FreeBSD 8.0-RELEASE amd64.

Test system installed via VMware Fusion 3.0 using 1 processor and 2GB of RAM. Several parameters for vm.kmem_size, vm.kmem_size_max were tried with no differences.

The panic doesn't seem to happen if ZFS is backed by IDE hard drives.


After clean install, added "zfs_enable=YES" to /etc/rc.conf. Went through ZFS tutorial at: This creates two 128MB files and creates a ZFS mirror pool backed by the two files. Tutorial then tries to demonstrate a ZFS failure mode. Commands as follows:

zpool create trout mirror /home/ocean/disk1 /home/ocean/disk2
mkfile 32m /trout/foo
dd if=/dev/random of=/home/ocean/disk1 bs=512 count=1
zpool scrub trout

At this point, the kernel panics.


More information about the freebsd-bugs mailing list