[c-nsp] Spanning-tree migration from MST to RSTP

[N. Max Pierson]

Hi List,

I am working at a new datacenter that has a spine/leaf (all Nexus 9ks)
topology. The spine switches (two of them) are configured for MST but all
of the leaf switches are running rapid-pvst. I would like to migrate the
spine's to rapid-pvst but I want to make sure i'm not missing anything when
I  go to do so. Currently spine2 is the root for all VLAN's. I want to make
spine1 the root for all VLAN's (and eventually enable peer-switch for
better convergence) so that this matches the vPC role of being primary and
also matches the vrrp primary roles as well.

So my question is can I just change on spine1 the priority for rapid-pvst
to 4096 on all VLAN's then change the spanning-tree mode to rapid-pvst and
only expect a few seconds of re-convergence (MAC flushing/learning/flooding
of BPDUs to the downstream switches and spine 2) and only have a few
seconds of traffic disruption?

I have migrated a datacenter from rapid-pvst to MST before and followed the
documentation from cisco on this (
https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/72844-MST.html)
which says to start at the distribution and work your way down to the
access layer but this is the reverse of that and I want to make sure I
don't lose the second spine when I make the changes on the first spine.

Thoughts or suggestions are welcome.

TIA,
Max