Server

Reseting drupal password with latest drupal version has become much harder task, before you could just MD5 user table and add new password, now the "salt" is added so it is a bit harder. There are two ways, with mysql and shell access, or with php file. First you can find here

https://drupal.org/node/1023428 - SSH and MySql
https://drupal.org/node/1556488 - PHP file

Before I talked about some troubleshooting and had some general discussions about caching
http://drupaldump.com/varnish-simple-troubleshooting-defaultvcl
http://drupaldump.com/boost-and-varnish-and-general-tips-and-rants-about...

Now I am going to talk about what to put in your default.vcl file and why.

Here is some simple troubleshooting for Varnish

If you want to have simple solution, cache with varnish for all anonymous users and for logged in users you disable varnish use this in your vcl

This topic has always been a big pain in the ass for me. Drupal takes a lot of resources, which means money for hosting, you should at least have VPS to have some decent hosting for drupal, but not to have OOMing and high CPU usage all the time, you should use different caching systems.

Boost

If you ever wondered how to setup permission and ownership of files on your drupal server installation, look no further, this article has all the good examples.

https://drupal.org/node/244924

So Varnish is really good caching thingy if you use drupal (or other stuff) so to see what it is doing and how, you can login to your server and try this commands.

varnishlog - See what Varnish is currently processing, you will get complete header info I think

varnishstat - Shows various information about varnish

varnishhist - Shows a histogram chart of the last 1,000 requests (by default) to the Varnish. Showing | as a hit on the cache and # as a miss. The more | to the left of the chart, the better.

Without a powerful server drupal administration online is very slow. As I have a multisite online, for some bigger changes I decided to take it offline to localhost and try to build/change things on my computer an then upload DB online. But first I needed to configure my localhost to work with multisite. Procedure is similar as on VPS with LAMP (having WAMP locally) but you need to change some different files.

So first thing you need to do is enable this possibility with

Enable Virtual Host

Maybe you are wondering the same thing as I, where the heck is my drush installed. Easiest way is to write "find / -name 'drush' -type d" and you will get info. So finally you know where that alisases.drushrc.php is and you can go and add configuration for drupal 6 to drupal 7 migration.

If this doesn't help you, try commands

which drush or drush status

Usually you would find drush in /usr/share/php/drush or /usr/share/drush and aliases file is in that directory as well.

Also as it is said in drush example.aliases.drushrc.php

Drush is fast for updateing modules, now there is also add on for upgrading modules from drupal 6 to drupal 7. You need to install http://drupal.org/project/drush_sup
Everything you need is in readme file, but the one important thing. You need to set alias for your new destination, your drupal 7 site version destination so you don't overrun drupal 6 and lose your original. But the problem is that you will get

Site alias not found: @test. See example.drushrc.php.

Another caching engine for drupal is APC, http://drupal.org/project/apc before you install module you need to install it on you linux. And before you install APC you need to install some other dependencies, otherwise you will get errors.

So you need to run

then finally you run