Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Wed, Jul 20, 2016 at 02:06:40PM -0400, David Bruzos wrote: > On Wed, Jul 20, 2016 at 07:00:33PM +0100, Trevor Hemsley wrote: > > On 20/07/16 17:34, David Bruzos wrote: > > > Hello all, I'm experiencing some kernel oops when using DRBD. I'm > > > not sure if the root cause of the problem is DRBD, but it appears > > > that DRBD resources are always affected by the oops and I've seen > > > other DRBD related messages on the web that look similar to mine. > > > > > > The system is a Xen dom0 Gentoo system, running kernel 4.4.6, Xen > > > 4.6, ZFS 0.6.5.7 and DRBD 8.4.5. The system runs very well while > > > it is running, but at some unpredictable point in time, it has > > > this problem. The DRBD resource appears to stop working all > > > together when this happens. It is a multi-volume DRBD resource on > > > top of ZFS zvols. > > > > My first step whenever I see xen and DRBD mentioned in the same sentence > > is to ask if you have disabled sendpage? > > > > echo "options drbd disable_sendpage=1" >> /etc/modprobe.d/drbd.conf > > > > then reload the drbd module. > > > Yes,: > # cat /etc/modprobe.d/drbd.conf: options drbd minor_count=254 disable_sendpage=1 > # cat /sys/module/drbd/parameters/disable_sendpage: Y > > Thanks for the reply. If this is sufficiently easy for you to reproduce, you could try to find out if this is kernel version dependend, or if using a newer DRBD module would change anything. Does it reproduce with drbd 8.4.8? Does it reproduce with non-xen? Does it reproduce with kernel.org 3.10, 4.0, 4.2? > > > * Here is the relevant output from dmesg when the event happens: > > > > > > [260175.411938] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 > > > [260175.412054] Oops: 0000 [#1] SMP > > > [260175.413309] CPU: 0 PID: 8884 Comm: drbd_w_vm_ex13- Tainted: P O 4.4.6-gentoo-xen0u #3 > > > [260175.413349] Hardware name: Supermicro AS -2022G-URF4+/H8DGU-LN4, BIOS 3.5a 09/25/2015 > > > [260175.413420] RIP: e030:[<ffffffff813fb602>] [<ffffffff813fb602>] __memcpy+0x12/0x20 > > > [260175.413874] Call Trace: > > > [260175.413892] [<ffffffff813fff95>] ? copy_from_iter+0x1f5/0x260 > > > [260175.413923] [<ffffffff8179ef25>] tcp_sendmsg+0x605/0xaf0 > > > [260175.413951] [<ffffffff817c9c45>] inet_sendmsg+0x65/0xa0 > > > [260175.415401] [<ffffffff817340a5>] kernel_sendmsg+0x35/0x50 > > > [260175.416848] [<ffffffffa0f5f8b1>] drbd_send+0xe1/0x200 [drbd] > > > [260175.418262] [<ffffffffa0f5fa79>] __send_command.isra.37+0xa9/0x1d0 [drbd] > > > [260175.419674] [<ffffffffa0f617a6>] drbd_send_dblock+0x286/0x640 [drbd] -- : Lars Ellenberg : LINBIT | Keeping the Digital World Running : DRBD -- Heartbeat -- Corosync -- Pacemaker DRBD® and LINBIT® are registered trademarks of LINBIT __ please don't Cc me, but send to list -- I'm subscribed