resume RBD mirror on another host
Hi, How RBD mirror tracks mirroring process, on local storage? Say, RBD mirror is running on host-1, when host-1 goes down, start RBD mirror on host-2. In that case, is RBD mirror on host-2 going to continue the mirroring? Thanks! Tony
On Thu, Jul 13, 2023 at 6:16 PM Tony Liu <tonyliu0592@hotmail.com> wrote:
Hi,
How RBD mirror tracks mirroring process, on local storage? Say, RBD mirror is running on host-1, when host-1 goes down, start RBD mirror on host-2. In that case, is RBD mirror on host-2 going to continue the mirroring?
Hi Tony, No, it's tracked on the RBD image itself -- meaning in RADOS. With journal-based mirroring it's the commit position in the journal (roughly). For snapshot-based mirroring, there is last_copied_object_number field on each mirror snapshot. Thanks, Ilya
On Thu, Jul 13, 2023 at 10:23 PM Ilya Dryomov <idryomov@gmail.com> wrote:
On Thu, Jul 13, 2023 at 6:16 PM Tony Liu <tonyliu0592@hotmail.com> wrote:
Hi,
How RBD mirror tracks mirroring process, on local storage? Say, RBD mirror is running on host-1, when host-1 goes down, start RBD mirror on host-2. In that case, is RBD mirror on host-2 going to continue the mirroring?
Hi Tony,
No, it's tracked on the RBD image itself -- meaning in RADOS.
To be clear, "no" here was meant to answer the "How RBD mirror tracks mirroring process, on local storage?" question. To answer the second question explicitly: yes, rbd-mirror daemon on host-2 will continue mirroring from where rbd-mirror daemon on host-1 left off. Thanks, Ilya
Super! Thanks Ilya! Tony ________________________________________ From: Ilya Dryomov <idryomov@gmail.com> Sent: July 13, 2023 01:30 PM To: Tony Liu Cc: dev@ceph.io; ceph-users@ceph.io Subject: Re: [ceph-users] resume RBD mirror on another host On Thu, Jul 13, 2023 at 10:23 PM Ilya Dryomov <idryomov@gmail.com> wrote:
On Thu, Jul 13, 2023 at 6:16 PM Tony Liu <tonyliu0592@hotmail.com> wrote:
Hi,
How RBD mirror tracks mirroring process, on local storage? Say, RBD mirror is running on host-1, when host-1 goes down, start RBD mirror on host-2. In that case, is RBD mirror on host-2 going to continue the mirroring?
Hi Tony,
No, it's tracked on the RBD image itself -- meaning in RADOS.
To be clear, "no" here was meant to answer the "How RBD mirror tracks mirroring process, on local storage?" question. To answer the second question explicitly: yes, rbd-mirror daemon on host-2 will continue mirroring from where rbd-mirror daemon on host-1 left off. Thanks, Ilya
participants (2)
-
Ilya Dryomov
-
Tony Liu