[Bug 205708] Kernel panic possibly happening while adding/removing/listing ZFS snapshot

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=205708

            Bug ID: 205708
           Summary: Kernel panic possibly happening while
                    adding/removing/listing ZFS snapshot
           Product: Base System
           Version: 10.2-RELEASE
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: freebsd-bugs at FreeBSD.org
          Reporter: root_dfjo1hpy at meo.ws
                CC: freebsd-amd64 at FreeBSD.org
                CC: freebsd-amd64 at FreeBSD.org

Hi,

recently my FreeBSD system running ZFS started to crash every now and then. I
think the bug is somehow associated with the amount of datastores*snapshots I'm
having.

The system was actually running fine with snapshots done/deleted every 10
minutes, every 30 minutes, every hour, 6 hours, 12 hours, 24 hours and every
week until it started to behave strange and started to crash.

I then rebooted the system, checked everything and even replaced hardware that
might have caused this (memory, CPU, motherboard, HBA, basically everything but
the disks itself) with the same or similar hardware that was available.

Then suddenly, the second crash, this time FreeBSD didn't do any kernel dump or
anything similar but just print the stack trace on the monitor and freeze. And
stupid I was I rebooted without taking a picture, but I remember reading the
same lines I had in the first crash (which is attached).

Stuff I changed about 1 day before the first crash happened:

sysctl vfs.zfs.l2arc_noprefetch=1
zfs set sync=disabled data
zfs set logbias=throughput data

The system performed faster after these changes, the main reason was that the
performance was not good enough to keep up with our virtual servers that we're
running from iSCSI and NFS4.


This is all I know at this time that should go in this bug report. Attached are
some files from the first crash that occurred.

-- 
You are receiving this mail because:
You are on the CC list for the bug.