We are able to bring the Sepia switches with us so we are not limited on network ports, space, power, or cooling.

We only have a 1Gb link into the Community Cage and we share with the other tenants so replication will be limited there.

If we end up using Proxmox, the backing storage will be Ceph anyway so we will have a Ceph cluster in Poughkeepsie before we ship the current Sepia gear.

Good to know that we can’t add the nodes later.  I’m thinking let’s (eventually) shrink the cluster to be a minimum number of useful hosts (all ivan + N reesi) and we can chuck them all in a rack together.  Anything running (e.g., teuth logs, home dirs) on the “Proxmox” Ceph cluster can be copied over after.

From: Gregory Farnum <gfarnum@redhat.com>
Date: Tuesday, March 25, 2025 at 1:42 AM
To: Patrick Donnelly <pdonnell@redhat.com>
Cc: David Galloway <David.Galloway@ibm.com>, sepia@ceph.com <sepia@ceph.io>
Subject: [EXTERNAL] Re: [sepia] Re: Migrating the LRC to IBM's lab

If we want to keep the existing LRC (which would be great), the
important part is the internal state of the system. So as Patrick
alludes to, we *could* create a single cluster that is stretched
across old and new labs, and then use CRUSH rule changes to move
everything into the new space.

I'm not sure this is easier than simply shipping the existing nodes
intact and then using them to seed a new LRC in-place, if we have a
solution to store what we need in the lab until that shipping happens.

To keep the historical aging of the cluster, we do need the existing
LRC nodes to be part of it when we generate the cluster, though — we
can't merge them later in any meaningful way. I'm not sure if that
changes your perception of how reasonable those options are, David.
-Greg

On Mon, Mar 24, 2025 at 9:17 AM Patrick Donnelly <pdonnell@redhat.com> wrote:
>
> On Mon, Mar 24, 2025 at 12:02 PM David Galloway <David.Galloway@ibm.com> wrote:
> > Buy new LRC gear, migrate what’s necessary, integrate old Sepia gear into “new” LRC
>
> I don't think we necessarily need to keep the old sepia LRC nodes. As
> long as we migrate everything to new hardware it should be good. I
> think the LRC can just steal 3-6 nodes from the hardware we already
> plan to purchase (for the upstream lab).
>
> I think the troublesome part will be the RADOS replication to the new
> site. Will we have the VPN straddling the two sites at some point?
>
>
> --
> Patrick Donnelly, Ph.D.
> He / Him / His
> Red Hat Partner Engineer
> IBM, Inc.
> GPG: 19F28A586F808C2402351B93C3301A3E258DD79D
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