Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Wed, Jul 09, 2014 at 09:26:49AM +0200, Lars Ellenberg wrote:
> On Wed, Jul 09, 2014 at 01:58:05AM +0000, Senne Vaeyens wrote:
> > Hi,
> >
> > I’m using 8.4.4 on CentOS 6.5
> > I try to configure an NFS server as explained by Craig Carl in the
> > following presentation:
> > http://www.slideshare.net/AmazonWebServices/nfs-and-cifs-options-for-aws-stg401-aws-reinvent-2013
> > , (youtube video of the presentation can be found here:
> > https://www.youtube.com/watch?v=xbuiIwEOCAs)
>
> Yeah, well, IMO, that is tecnically nonsense.
Ok, that may come accross as rude or harsh.
What I mean is, DRBD is NOT a host based mirroring solution,
but a replication solution, which is not the same thing.
If you want to do host based mirroring, use md raid.
If you want to do replication, between instances,
use DRBD.
You can clearly use DRBD to *replicate* from one instance
in one zone to an other instance in an other zone,
or from instance on "fast" storage to instance on "durable" storage.
This makes perfectly sense.
This is what DRBD was designed for.
But, in my opinion, you should not try to use DRBD to "mirror" from one
block storage to an other block storage *within the same instance*.
For that, md raid would likely be the better solution.
That is what md raid has been designed for.
I'm clearly biased towards DRBD,
and I'm happy to hear that you all like to use DRBD.
But, even if it can do something,
it is not always the best fit.
Not for everything.
Simply use the right tool for the job.
> > Craig explains on slide 12 how you configure a local mirror with brbd;
> >
> > It goes somewhat like this...
> >
> > resource r0 {
> > on az-a{
> > device /dev/drbd0;
> > disk /dev/md0;
> > address 10.1.1.1:7789;
> > meta-disk internal;
> > }
> > on az-a{
> > device /dev/drbd1;
> > disk /dev/md1;
> > address 10.1.1.1:7789;
> > meta-disk internal;
> > }
> > }
>
> Which is simply wrong and won't even parse.
> So why don't you ask Craig how he really did it?
> Clearly not the way he presented it in those slides.
>
> But see there:
> http://www.gossamer-threads.com/lists/drbd/users/26473#26473
>
> Still, it does not make sense.
> DRBD is the wrong tool for the job.
> Use md raid for host based mirroring.
>
>
> --
> : 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
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--
: 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