diff --git a/lib/tasks/uploads.rake b/lib/tasks/uploads.rake
index 73118c6b15d..ef9e3cbbb84 100644
--- a/lib/tasks/uploads.rake
+++ b/lib/tasks/uploads.rake
@@ -277,3 +277,141 @@ def regenerate_missing_optimized
     missing_uploads.sort.each { |u| puts u }
   end
 end
+
+task "uploads:migrate_to_new_pattern" => :environment do
+  ENV["RAILS_DB"] ? migrate_to_new_pattern : migrate_to_new_pattern_all_sites
+end
+
+def migrate_to_new_pattern_all_sites
+  RailsMultisite::ConnectionManagement.each_connection { migrate_to_new_pattern }
+end
+
+def migrate_to_new_pattern
+  db = RailsMultisite::ConnectionManagement.current_db
+
+  puts "Migrating uploads to new pattern for '#{db}'..."
+  migrate_uploads_to_new_pattern
+
+  puts "Migrating optimized images to new pattern for '#{db}'..."
+  migrate_optimized_images_to_new_pattern
+
+  puts "Done!"
+end
+
+def migrate_uploads_to_new_pattern
+  if Upload.where(sha1: nil).exists?
+    puts "Computing missing SHAs..."
+
+    Upload.where(sha1: nil).find_each do |upload|
+      path = Discourse.store.path_for(upload)
+      size = File.size(path) rescue 0
+      if size > 0
+        upload.sha1 = Digest::SHA1.file(path).hexdigest
+        upload.save
+        putc "."
+      else
+        upload.destroy
+        putc "X"
+      end
+    end
+
+    puts
+  end
+
+  puts "Moving uploads to new location..."
+  Upload.where.not(sha1: nil)
+        .where("url LIKE '/uploads/%'")
+        .where("url NOT LIKE '/uploads/%/original/%'")
+        .find_each do |upload|
+    path = Discourse.store.path_for(upload)
+    if File.exists?(path)
+      file = File.open(path)
+      # copy file to new location
+      url = Discourse.store.store_upload(file, upload)
+      file.try(:close!) rescue nil
+      # remap URLs
+      remap(upload.url, url)
+      # remove old file
+      FileUtils.rm(path, force: true) rescue nil
+      putc "."
+    else
+      # upload.destroy
+      putc "X"
+    end
+  end
+
+  puts
+end
+
+def migrate_optimized_images_to_new_pattern
+  if OptimizedImage.where(sha1: nil).exists?
+    puts "Computing missing SHAs..."
+
+    OptimizedImage.where(sha1: nil).find_each do |optimized_image|
+      path = Discourse.store.path_for(optimized_image)
+      size = File.size(path) rescue 0
+      if size > 0
+        optimized_image.sha1 = Digest::SHA1.file(path).hexdigest
+        optimized_image.save
+        putc "."
+      else
+        optimized_image.destroy
+        putc "X"
+      end
+    end
+
+    puts
+  end
+
+  puts "Moving optimized images to new location..."
+  OptimizedImage.where.not(sha1: nil)
+                .where("width > 0 AND height > 0")
+                .where("url LIKE '/uploads/%/_optimized/%'")
+                .where("url NOT LIKE '/uploads/%/optimized/%'")
+                .find_each do |optimized_image|
+    path = Discourse.store.path_for(optimized_image)
+    if File.exists?(path)
+      file = File.open(path)
+      # copy file to new location
+      url = Discourse.store.store_optimized_image(file, optimized_image)
+      file.try(:close!) rescue nil
+      # remap URLs
+      remap(optimized_image.url, url)
+      # remove old file
+      FileUtils.rm(path, force: true) rescue nil
+      putc "."
+    else
+      optimized_image.destroy
+      putc "X"
+    end
+  end
+
+  puts
+end
+
+REMAP_SQL ||= "
+  SELECT table_name, column_name
+    FROM information_schema.columns
+   WHERE table_schema = 'public'
+     AND is_updatable = 'YES'
+     AND (data_type LIKE 'char%' OR data_type LIKE 'text%')
+ORDER BY table_name, column_name
+"
+
+def remap(from, to)
+  connection ||= ActiveRecord::Base.connection.raw_connection
+  remappable_columns ||= connection.async_exec(REMAP_SQL).to_a
+
+  remappable_columns.each do |rc|
+    table_name = rc["table_name"]
+    column_name = rc["column_name"]
+    begin
+      connection.async_exec("
+        UPDATE #{table_name}
+           SET #{column_name} = REPLACE(#{column_name}, $1, $2)
+         WHERE #{column_name} IS NOT NULL
+           AND #{column_name} <> REPLACE(#{column_name}, $1, $2)", [from, to])
+    rescue
+    end
+  end
+end