Upgrading Drupal

For a complicated website, with ~25 custom modules and applications for users, and ~25 public (well documented) drupal modules, how long does it take a drupal developer typically to migrate from drupal 6 to 7?

How much time and cost should I prepare for?

Thanks.

I am upgrading my site from D6 to D7. Everything has gone well so far by following the upgrade documentation except for trying to migrate my embedded video fields. The CCK migrator does not work and throws this error when I try to use on these fields:

Hi all

I am in the process of migrating a drupal site currently version 6.22. I am also a new user to drupal but experienced with wordpress.

After upgrading from drupal 6 to 7 I want to turn a public file field into a private. Since it contains data the system does not allow this.

If I go to field settings it says: "There is data for this field in the database. The field settings can no longer be changed."

Is there a way to do this?

Hello,

i get this message on admin/modules

the whole message is :

Node Debug Information Report 7.15
Assist in resolving the "warning: Invalid argument supplied for foreach() in [path to]/modules/taxonomy/taxonomy.module on line 1241." problem
This version is not compatible with Drupal 7.x and should be replaced.

When I try to update through sitename/update.php I get to the thirds step which lists 5 pending updates. Here's that list:

system module

7073 - Add binary to {file_managed}, in case system_update_7034() was run without it.
7074 - This update has been removed and will not run.

field module

7002 - Split the all-inclusive field_bundle_settings variable per bundle.

node module

7013 - Change {node}.vid default value from 0 to NULL to avoid deadlock issues on MySQL.

user module