Login | Register For Free | Help
Search for: (Advanced)

Mailing List Archive: DRBD: Users

Howto prevent write operations on Primary when in WFConnection

 

 

DRBD users RSS feed   Index | Next | Previous | View Threaded


joel at gluefinance

Oct 1, 2009, 10:47 AM

Post #1 of 2 (635 views)
Permalink
Howto prevent write operations on Primary when in WFConnection

We are about to go live with a DRBD / PostgreSQL installation running on
Debian 5, 2.6.26-2-amd64.

Is there a way to prevent write operations on the Primary in case it loses
connection with the Secondary?

Why would I want to do that?
Because if the Primary goes down, while the Secondary is in state
UpToDate/DUnknown, it is not possible to know for sure if the Primary has
been modified after the Secondary lost its connection with the Primary.
But if the Primary would refuse to perform any write operations if the
replication link goes down to the Secondary, it would be totally safe to
promote the Secondary to Primary.

I do of course realize such a configuration would mean the entire system
would become inaccessible if the Secondary would go down, but that is also
my wish since we cannot risk losing any data.

Any ideas are welcome.

Thanks.
--
View this message in context: http://www.nabble.com/Howto-prevent-write-operations-on-Primary-when-in-WFConnection-tp25703586p25703586.html
Sent from the DRBD - User mailing list archive at Nabble.com.

_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user


lars.ellenberg at linbit

Oct 2, 2009, 12:51 AM

Post #2 of 2 (589 views)
Permalink
Re: Howto prevent write operations on Primary when in WFConnection [In reply to]

On Thu, Oct 01, 2009 at 10:47:41AM -0700, Joel Jacobson wrote:
>
> We are about to go live with a DRBD / PostgreSQL installation running on
> Debian 5, 2.6.26-2-amd64.
>
> Is there a way to prevent write operations on the Primary in case it loses
> connection with the Secondary?
>
> Why would I want to do that?
> Because if the Primary goes down, while the Secondary is in state
> UpToDate/DUnknown, it is not possible to know for sure if the Primary has
> been modified after the Secondary lost its connection with the Primary.
> But if the Primary would refuse to perform any write operations if the
> replication link goes down to the Secondary, it would be totally safe to
> promote the Secondary to Primary.
>
> I do of course realize such a configuration would mean the entire system
> would become inaccessible if the Secondary would go down, but that is also
> my wish since we cannot risk losing any data.
>
> Any ideas are welcome.

DRBD does have various mechanisms to achieve what you want to do,
and yes, it _can_ safely be still available in most cases.

http://www.linbit.com/en/products-services/drbd-consulting/


--
: 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
_______________________________________________
drbd-user mailing list
drbd-user [at] lists
http://lists.linbit.com/mailman/listinfo/drbd-user

DRBD users RSS feed   Index | Next | Previous | View Threaded
 
 


Interested in having your list archived? Contact Gossamer Threads
 
  Web Applications & Managed Hosting Powered by Gossamer Threads Inc.