Re: [drbd] Kernel panic - not syncing: Out of memory and no killable processes...

[Fengguang Wu <fengguang.wu@intel.com>]

Hi Philipp,

On Tue, Mar 18, 2014 at 03:30:16PM +0100, Lars Ellenberg wrote:
> On Tue, Mar 18, 2014 at 10:07:17PM +0800, Fengguang Wu wrote:
> > Greetings,
> > 
> > We get the below OOM errors in our KVM boot tests and they are
> > bisected to
> > 
> > commit 23361cf32b58efdf09945a64e1d8d41fa6117157
> 
> We have been there before:

Yeah, sorry I forgot that.. Just tried the suggested
"drbd.minor_count=8" and it helps! Thank you all for the tip!

Cheers,
Fengguang

> .---
> | Date: Wed, 12 Jun 2013 18:11:43 +0800
> | From: Fengguang Wu <fengguang.wu@intel.com>
> | To: Philipp Reisner <philipp.reisner@linbit.com>, drbd-user@lists.linbit.com, linux-kernel@vger.kernel.org
> | Subject: Re: [drbd?] Kernel panic - not syncing: Out of memory and no killable processes...
> | Message-ID: <20130612101143.GA13837@localhost>
> | 
> | On Tue, Jun 11, 2013 at 05:33:27PM +0200, Lars Ellenberg wrote:
> | > On Fri, Jun 07, 2013 at 10:31:54AM +0800, Fengguang Wu wrote:
> | > > Greetings,
> | > >
> | > > My "kvm -m 256" reliably goes Out Of Memory after this commit.  It may
> | > > not be the only one that eats up the memory, however I wonder how much
> | > > memory consumption this commit added? Thanks!
> 
> ...
> 
> | > We scale certain mempools and reserves with
> | > DRBD_MAX_BIO_SIZE/PAGE_SIZE * minor_count.
> | >
> | > DRBD_MAX_BIO_SIZE has been increased by this patch,
> | > resulting in more memory allocated to those reserved pools.
> | >
> | > Please just scale down the "minor_count" parameter.
> | > You can use the module parameter (e.g. modprobe drbd minor_count=8),
> | > or, compiled in, use the kernel command line parameter drbd.minor_count=8.
> | >
> | > Though "minor_count" at some point used to be the hard limit for the number of
> | > minor devices (allocation of an array of corresponding size), that has
> | > long since changed, and now it is really only used as scaling factor for
> | > these mempools.
> | 
> | Got it, thank you very much for the helpful tips and explanations!
> | I'll add the drbd.minor_count=8 option.
> | 
> | Thanks,
> | Fengguang
> `---
> 
> Does that help?
> 
> -- 
> : 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.