From 6e21ebe8c8d0c9b0f0a8d11b71d064b3f9ca0ccf Mon Sep 17 00:00:00 2001
From: Chris Remus <6430200+chris-remus@users.noreply.github.com>
Date: Tue, 10 Dec 2019 12:00:13 -0500
Subject: [PATCH] Merge PR #213: Update cosmoshub-2.md

---
 docs/migration/cosmoshub-2.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/migration/cosmoshub-2.md b/docs/migration/cosmoshub-2.md
index d611bac9..781f5fd4 100644
--- a/docs/migration/cosmoshub-2.md
+++ b/docs/migration/cosmoshub-2.md
@@ -77,6 +77,8 @@ Prior to exporting `cosmoshub-2` state, validators are encouraged to take a full
 export height before proceeding. Snapshotting depends heavily on infrastructure, but generally this
 can be done by backing up the `.gaiacli` and `.gaiad` directories.
 
+It is critically important to back-up the `.gaiad/data/priv_validator_state.json` file after stopping your gaiad process. This file is updated every block as your validator participates in a consensus rounds. It is a critical file needed to prevent double-signing, in case the upgrade fails and the previous chain needs to be restarted.
+
 In the event that the upgrade does not succeed, validators and operators must downgrade back to
 v0.34.6+ of the _Cosmos SDK_ and restore to their latest snapshot before restarting their nodes.