not able to start (bootstrap) the Drupal database on Aegir upgrade

https://gist.github.com/2258564 (server config pre upgrade, post available if needed)

Just attempted an upgrade to 2.0.3 and had the following errors and warnings. End result seemed to be all sites on "under maintenace" pages, and CGP was also not displaying any graphs. Reloaded a server backup after that, but saved a copy of the same files as in the above link from the botched upgrade in case they'd be handy. I've never had upgrade troubles before, except having to add that "upload_progress uploads 1m;" to the config file to get nginx to start properly. Do any of these look familiar? Thanks!

nginx on server.mysite.com could not be restarted.      [warning]
Changes might not be available until this has been done.
(error: Reloading nginx configuration: nginx: [warn] the
"limit_zone" directive is deprecated, use the
"limit_conn_zone" directive instead in
/etc/nginx/conf.d/aegir.conf:76
nginx: [warn] conflicting server name "_" on
173.xxx.xxx.xxx:443, ignored

Drush was not able to start (bootstrap) the Drupal database. [error]
Hint: This error often occurs when Drush is trying to
bootstrap a site that has not been installed or does not have
a configured database.

Drush was attempting to connect to : 
  Drupal version    : 6.24
  Site URI          : aegir.mysite.com
  Database driver   : mysqli
  Database hostname : server.mysite.com
  Database username : aegirmysite_0
  Database name     : aegirmysite_0
  Default theme     : garland
  Administration theme: garland
  PHP configuration : /usr/local/lib/php.ini
  Drush version     : 4.6-dev
  Drush configuration:
/var/aegir/host_master/011/sites/aegir.mysite.com/drushrc.php
/var/aegir/host_master/011/drushrc.php
  Drush alias files :
/var/aegir/.drush/hostmaster.alias.drushrc.php
/var/aegir/.drush/server_master.alias.drushrc.php
/var/aegir/.drush/platform_011.alias.drushrc.php
/var/aegir/.drush/platform_010.alias.drushrc.php
  Drupal root       : /var/aegir/host_master/011
  Site path         : sites/aegir.mysite.com
  Modules path      : sites/aegir.mysite.com/modules
  Themes path       : sites/aegir.mysite.com/themes
  %paths            : Array

nginx on server.mysite.com could not be restarted.      [warning]
Changes might not be available until this has been done.
(error: Reloading nginx configuration: nginx: [warn] the
"limit_zone" directive is deprecated, use the
"limit_conn_zone" directive instead in
/etc/nginx/conf.d/aegir.conf:76
nginx: [warn] conflicting server name "_" on
173.230.158.212:443, ignored
nginx: the configuration file /etc/nginx/nginx.conf syntax is
ok
nginx: [emerg] zero size shared memory zone "uploads"
nginx: configuration file /etc/nginx/nginx.conf test failed)