[DRBD-user] Primary device hangs when syncing with secondary

[Sean Dwyer]

Thanks for the help. As I'm typing the boxes are in the middle of a SyncingAll, and my app is creating files over the Samba share. Seems to be working great.

----------------- Original message -----------------
From: "Lars Ellenberg" <Lars.Ellenberg at linbit.com>
To: drbd-user at lists.linbit.com
Date: 6/2/2004 12:45:22 PM
Subject: Re: [DRBD-user] Primary device hangs when syncing with secondary

/ 2004-06-02 11:48:39 -0700
\ Sean Dwyer:
> I have replication set up between two boxes with drbd over a crossover
> cable using protocol C. I have /dev/nb0 mounted at /mnt/nb0 on the
> primary box, which is then shared via Samba3. I've been testing the
> setup with an app on a third box running Win2K that creates random
> files on the Samba share as fast as it can.
> In order to simulate a failure, I tried rebooting the drbd secondary
> box. The problem is that when the secondary comes back up and drbd
> initiates a sync, the Samba share seems to hang (i.e. the app on the
> Win2K box can't create any files) until the syncing completes. Is this
> normal?
> From what I've read, the drbd device on the primary should perform
> normally during a sync.

well, not exactly "normally".
resynchronization is, depending on your settings for sync-{min,max,nice}
considerable load on the system... maybe the samba server just is that
slow accessing the device (because the sync is that high in priority)
that the resync finishes before the samba managed to get its requests
through...

play with those sync settings.

 Lars Ellenberg