notes about manual steps required in this update

DEPLOYMENT-NOTES.rst

 Deployment notes
 ================
 
+- 2021-12-20
+
+  `https://whetstone.privatestorage.io/privatestorage/privatestorageops/-/issues/399`_ requires moving the PaymentServer database on the ``payments`` host onto a new dedicated filesystem.
+
+  Before deploying this version:
+
+  1. Put a disk label on the new dedicated volume ::
+
+    nix-shell -p parted --run 'parted /dev/nvme1n1 mklabel msdos'
+
+  2. Put a properly aligned partition in the new disk label ::
+
+    nix-shell -p parted --run 'parted /dev/nvme1n1 mkpart primary ext2 4096s 4G'
+
+  3. Create a labeled filesystem on the partition ::
+
+    mkfs.ext4 -L voucher-database /dev/nvme1n1p1
+
+  4. Mount the new filesystem ::
+
+    systemctl restart var-lib-voucher-database.mount
+
+  5. Deploy the PrivateStorageio update.
+
+  6. Move the database file to the new location ::
+
+    mv -iv /var/lib/zkapissuer/vouchers.sqlite3 /var/lib/zkapissuer-vouchers
+
+  7. Clean up the old state directory ::
+
+     rm -ir /var/lib/zkapissuer
+
 - 2021-10-12 The secret in ``private-keys/grafana-slack-url`` needs to be changed to remove the ``SLACKURL=`` prefix.
 
 - 2021-09-30 `Enable alerting <https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/185>`_ needs a secret in ``private-keys/grafana-slack-url`` looking like the template in ``morph/grid/local/private-keys/grafana-slack-url`` and pointing to the secret API endpoint URL saved in `this 1Password entry <https://privatestorage.1password.com/vaults/7flqasy5hhhmlbtp5qozd3j4ga/allitems/cgznskz2oix2tyx5xyntwaos5i>`_ (or create a new secret URL at https://www.slack.com/apps/A0F7XDUAZ).
@@ -15,4 +47,3 @@ Deployment notes
 
    chmod 750 /var/lib/zkapissuer
    chmod 640 /var/lib/zkapissuer/vouchers.sqlite3
-