Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Sun, Dec 09, 2012 at 07:30:48PM +0100, Muc Reb wrote: > Hello, > > I've been using drbd for about 5 years now, and it has been working great. > > Recently we modified the setup, moved a couple of servers around, so drbd > should replicate over a 20 Mbit/sec WAN line. > > I've changed from Protocol C to A, and enabled Ahead/Behind mode. It seems > to work, but after some time, some of the resources stuck in Ahead/Behind > mode and never resync again unless I disconnect and reconnect the resource. > > It looks like this on the Primary: > cat /proc/drbd > version: 8.4.1 (api:1/proto:86-100) > GIT-hash: bb796da897912034a90003910f69ae0a2c10cf44 build by root at node1, > 2012-06-04 13:02:39 > [..] > 13: cs:Ahead ro:Primary/Secondary ds:UpToDate/Inconsistent A r----- > ns:9428820 nr:0 dw:446339296 dr:931364896 al:280851 bm:66801 lo:0 pe:0 > ua:0 ap:0 ep:1 wo:n oos:1389708 > > A minute later: > > 13: cs:Ahead ro:Primary/Secondary ds:UpToDate/Inconsistent A r----- > ns:9428820 nr:0 dw:446340428 dr:931364948 al:280851 bm:66801 lo:0 pe:0 > ua:0 ap:0 ep:1 wo:n oos:1389728 > > This seems like a bug to me, and it has already been reported by someone > else in August: > http://lists.linbit.com/pipermail/drbd-user/2012-August/018934.html > > I've also created a virtualised testsetup with two nodes with 8.4.2, and I > could reach this state, so it is fairly reproducible. The problem seems to > be happening when the node switches from SyncSource to Ahead mode without > finishing synchronization, i.e. I finish some writing to the drbd device, > then wait a few seconds so the node starts to sync, then I start writing > again. > > On the productive system it happens on resources which has the most writes. We are aware of this problem. Up to now we failed to reproduce it, though, so we don't have a fix yet. -- : 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. __ please don't Cc me, but send to list -- I'm subscribed