Upgrading Drupal

Hello, I've read a lot of documentation before posting this but I can't find a solution. I'm trying to update Drupal 7.34 to the last recommendation (7.36), so I use a command I've found should work, but it doesn't (or probably I'm doing something wrong).

I use the Shell black console. First, the command line that appears to me is this:
aparecidaconde%/home/u203381877/public_html>

Then, I write:
drush pm-update

And clic Send.

And nothing happens.

Last night, I attempted to apply some necessary updates, and our website immediately went into "site under maintenance" mode with the following error message:

Fatal error: Call to undefined function entity_property_info_cache_clear() in /home/txrehaba/public_html/sites/all/modules/entity/entity.module on line 788

Now I cannot login to the website or perform any other privileges.

Can someone shed some light on this issue?

The upgrade seems to have worked except for
Following error occurred
FileOp Failure on: /home/mysite/public_html/jim/drupal-7.36/.gitignore: No such file or directory
for the following files:

.gitignore

authorize.php

cron.php

index.php

install.php

update.php

web.config

xmlrpc.php

Hi,
I have to migrate 4 sites with allmost the same theme, but with different content to drupal 7 from drupal 6 and it looks like a nightmare, and I am not yet half way true.
I add this topic to get a complete working scenario, and may be some hints or easier stepts for the next sites.

Does anybody know the exact way Drupal 8 could be upgraded , mean from 8.0.0 to the last beta version (8.0.0.beta 9)?

I tried to upgrade via ftp by removing all files and folders except "sites" and then replacing with the same files and folders from last release, but without any result (non functioning/not responding website).

I have a fairly large subscription based site (http://thehappyscientist.com) that is currently running Drupal 6. I want to upgrade to Drupal 7, and at the same time, I want to rebuild much of the site. Over the past seven years, the site has changed, and many of the pages are out of date, old formats, old content types, etc. This seems like a good time to do some house cleaning.