Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Mon, Jan 28, 2013 at 05:57:43PM +0100, Lars Ellenberg wrote: > On Mon, Jan 28, 2013 at 04:04:32PM +0100, Matthias Hensler wrote: > > Hi, > > > > On Mon, Jan 28, 2013 at 03:26:49PM +0100, Felix Frank wrote: > > > On 01/26/2013 06:19 PM, Matthias Hensler wrote: > > > > Jan 26 15:32:21 lisa kernel: block drbd12: IO ERROR: neither local nor remote data, sector 0+0 > > > > Jan 26 15:32:21 lisa kernel: block drbd9: IO ERROR: neither local nor remote data, sector 0+0 > > > > > > I'm not at all sure about this, but this does seem to indicate that > > > the peer either has disk problems of its own (not likely) or otherwise > > > cannot access this specific (first?) sector. > > > > I do not think that there were any disk problems on the peer. In fact I > > did reboot all virtual machines on the peer side prior to replacing the > > failed disk. Everything went smooth from there. > > > Did you actually see DRBD pass errors up the stack > (file systems remounting read-only, guest VMs noticing IO error), > or have you "only" been scared by above log message. > > > If the latter, we may need to do some "cosmetic surgery". > > If the former, and this node still had an established connection to a > healthy peer device, we'd have a "real" bug. Ok. I think we may in fact have a real bug there. I still need to reproduce and double check, but it looks like "empty flushes" (file system barriers) on a Diskless Primary may be affected, obviously only on systems that do support those, which is drbd 8.3.14 and 8.3.15, on kernels that implement "barrier" as REQ_FLUSH/REQ_FUA (not REQ_BARRIER). drbd 8.4 should be good. We'll see what we can do. -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.