Re: RBD Mirror DR Testing

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Nov 21, 2019 at 8:49 AM Vikas Rana <vrana@xxxxxxxxxxxx> wrote:
>
> Thanks Jason for such a quick response. We are on 12.2.10.
>
> Checksuming a 200TB image will take a long time.

How would mounting an RBD image and scanning the image be faster? Are
you only using a small percentage of the image?

> To test the DR copy by mounting it, these are the steps I'm planning to follow
> 1. Demote the Prod copy and promote the DR copy
> 2. Do we have to recreate the rbd mirror relationship going from DR to primary?
> 3. Mount and validate the data
> 4. Demote the DR copy and promote the Prod copy
> 5. Revert the peer relationship if required?
>
> Did I do it right or miss anything?

You cannot change the peers or you will lose the relationship. If you
insist on your course of action, you just need to be configured for
two-way mirroring and leave it that way.

>
> Thanks,
> -Vikas
>
> -----Original Message-----
> From: Jason Dillaman <jdillama@xxxxxxxxxx>
> Sent: Thursday, November 21, 2019 8:33 AM
> To: Vikas Rana <vrana@xxxxxxxxxxxx>
> Cc: ceph-users <ceph-users@xxxxxxxxxxxxxx>
> Subject: Re:  RBD Mirror DR Testing
>
> On Thu, Nov 21, 2019 at 8:29 AM Vikas Rana <vrana@xxxxxxxxxxxx> wrote:
> >
> > Hi all,
> >
> >
> >
> > We have a 200TB RBD image which we are replicating using RBD mirroring.
> >
> > We want to test the DR copy and make sure that we have a consistent copy in case primary site is lost.
> >
> >
> >
> > We did it previously and promoted the DR copy which broken the DR copy from primary and we have to resync the whole 200TB data.
> >
> >
> >
> > Is there any correct way of doing it so we don’t have to resync all 200TB again?
>
> Yes, create a snapshot on the primary site and let it propagate to the non-primary site. Then you can compare checksums at the snapshot w/o having to worry about the data changing. Once you have finished, delete the snapshot on the primary site and it will propagate over to the non-primary site.
>
> >
> >
> > Can we demote current primary and then promote the DR copy and test and then revert back? Will that require the complete 200TB sync?
> >
>
> It's only the forced-promotion that causes split-brain. If you gracefully demote from site A and promote site B, and then demote site B and promote site A, that will not require a sync. However, again, it's probably just easier to use a snapshot.
>
> >
> > Thanks in advance for your help and suggestions.
> >
> >
> >
> > Thanks,
> >
> > -Vikas
> >
> > _______________________________________________
> > ceph-users mailing list
> > ceph-users@xxxxxxxxxxxxxx
> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
>
>
> --
> Jason
>
>


-- 
Jason

_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com




[Index of Archives]     [Information on CEPH]     [Linux Filesystem Development]     [Ceph Development]     [Ceph Large]     [Ceph Dev]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [xfs]


  Powered by Linux