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, Feb 02, 2009 at 01:23:51PM +0100, Rainer Sabelka wrote: > Hi, > > I'm using DRBD (0.8.12) on a pair of servers in separate locations connected > by an (almost) dedicated 1GBit ethernet link. > This connection has become unreliabe in a way that from time to time we see a > packet loss up to 30 percent. > During the these phases of high packet loss, access to the DRBD device blocks > for several minutes and the applications accessing the disk become completely > unresponsive. > > While we are trying to fix the network connetion in the first place I wonder > if I can do something with DRBD to work around this problem. > > From what I see in the logfiles It seems that DRBD detects the network > failure, diconnects, and immediately trys to reconnect. Then it stays for > several minutes in the WFBitMapS state. > It seems that any access to the DRBD device during this time blocks until the > state SyncSource is reached. > If the packet loss on the network confinus for a longer periode this > disconnect-reconnect cycle repeats several times. > The result is that a disturbance in the network connection between the servers > basically supends all running services which depend on DRBD. > > To work around the problem I've now put DRBD into stand alone mode. > Is there anything else I can do about this? fix the network link? well, seriously: what would you like DRBD to do? we are always open for suggestions * for scenarios we did not yet think about, * for ideas how to "best" handle those scenarios just mail us a wishlist. > -Rainer > > --- > > PS: syslog output and drbd.conf: > > on server2 (primary): > > Jan 30 11:21:33 server2 kernel: drbd0: [drbd0_worker/13962] sock_sendmsg time > expired, ko = 19 if you configure your ko count smaller, then if it actually reaches zero, drbd stays disconnected (StandAlone), until you tell it to reconnect explicitly. -- : 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