[DRBD-user] incompatible after-sb-0pri settings

Lonni J Friedman netllama at gmail.com
Fri Sep 21 16:43:14 CEST 2012

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


On Fri, Sep 21, 2012 at 4:30 AM, Felix Frank <ff at mpexnet.de> wrote:
> Hi,
>
> two remarks inline.
>
> On 09/20/2012 09:32 PM, Lonni J Friedman wrote:
>>                 after-sb-1pri discard-secondary;
>
> This is you signing up for grotesque data loss under unfortunate
> circumstances.
>
> I advise to never discard anything but zero-changes automatically.

The documentation only lists the discard-zero-changes policy for
after-sb-0pri.  Is 'consensus' what you are recommending?

>
>> I don't understand how this is incompatible.  At least the
>> documentation doesn't make any mention of what would make this
>> incompatible.
>
> We have yet to see the configuration of the peer node.

Do you mean *.res or something else?  If so, it is currently this on
both nodes (primary & secondary):
########
resource r0 {
	device    /dev/drbd0;
	disk      /dev/sdb1;
	meta-disk internal;
	handlers {
                split-brain "/usr/lib/drbd/notify-split-brain.sh root";
        }
        net {
                after-sb-0pri discard-zero-changes;
                after-sb-1pri consensus;
                after-sb-2pri disconnect;
        }
	syncer {
		rate 30M;
		verify-alg sha1;
		csums-alg md5;
	}
	on farm-ljf0 {
		address   10.31.99.165:7789;
	}
	on farm-ljf1 {
		address   10.31.99.166:7789;
	}
}
########

>
> Test wether both nodes have actually loaded the current configuration,
> either using drbdsetup <minor> show or drbdadm adjust --noop.

The second command doesn't work:
# drbdadm adjust --noop
drbdadm: unrecognized option '--noop'
try 'drbdadm help'

Hopefully this is what you need.  Both of these were run immediately
after running 'drbdadm adjust r0' on each node.

First the primary:
##########
# drbdsetup 0 show
disk {
	size            	0s _is_default; # bytes
	on-io-error     	pass_on _is_default;
	fencing         	dont-care _is_default;
	max-bio-bvecs   	0 _is_default;
}
syncer {
	rate            	30720k; # bytes/second
	after           	-1 _is_default;
	al-extents      	127 _is_default;
	csums-alg       	"md5";
	verify-alg      	"sha1";
	on-no-data-accessible	io-error _is_default;
	c-plan-ahead    	0 _is_default; # 1/10 seconds
	c-delay-target  	10 _is_default; # 1/10 seconds
	c-fill-target   	0s _is_default; # bytes
	c-max-rate      	102400k _is_default; # bytes/second
	c-min-rate      	4096k _is_default; # bytes/second
}
_this_host {
	device			minor 0;
	disk			"/dev/sdb1";
	meta-disk		internal;
}
##########

And the secondary:
##########
# drbdsetup 0 show
disk {
	size            	0s _is_default; # bytes
	on-io-error     	pass_on _is_default;
	fencing         	dont-care _is_default;
	max-bio-bvecs   	0 _is_default;
}
net {
	timeout         	60 _is_default; # 1/10 seconds
	max-epoch-size  	2048 _is_default;
	max-buffers     	2048 _is_default;
	unplug-watermark	128 _is_default;
	connect-int     	10 _is_default; # seconds
	ping-int        	10 _is_default; # seconds
	sndbuf-size     	0 _is_default; # bytes
	rcvbuf-size     	0 _is_default; # bytes
	ko-count        	0 _is_default;
	after-sb-0pri   	discard-zero-changes;
	after-sb-1pri   	consensus;
	after-sb-2pri   	disconnect _is_default;
	rr-conflict     	disconnect _is_default;
	ping-timeout    	5 _is_default; # 1/10 seconds
	on-congestion   	block _is_default;
	congestion-fill 	0s _is_default; # byte
	congestion-extents	127 _is_default;
}
syncer {
	rate            	30720k; # bytes/second
	after           	-1 _is_default;
	al-extents      	127 _is_default;
	csums-alg       	"md5";
	verify-alg      	"sha1";
	on-no-data-accessible	io-error _is_default;
	c-plan-ahead    	0 _is_default; # 1/10 seconds
	c-delay-target  	10 _is_default; # 1/10 seconds
	c-fill-target   	0s _is_default; # bytes
	c-max-rate      	102400k _is_default; # bytes/second
	c-min-rate      	4096k _is_default; # bytes/second
}
protocol C;
_this_host {
	device			minor 0;
	disk			"/dev/sdb1";
	meta-disk		internal;
	address			ipv4 10.31.99.166:7789;
}
_remote_host {
	address			ipv4 10.31.99.165:7789;
}
##########


Apparently the primary has not loaded the configuration, but I don't
understand why.  From the primary:

# drbd-overview
  0:r0  StandAlone Primary/Unknown   UpToDate/DUnknown r-----
/mnt/sdb1 xfs       15G 33M  15G 1%

>From the secondary:
# drbd-overview
  0:r0  WFConnection Secondary/Unknown UpToDate/DUnknown C r-----


thanks for your help.



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