Questions[cross-platform](server)

We have a educational system (federated microservices that are running mostly on AWS EC2, RDS MySQL and a message queue) that is already distributed across regions, primarily for latency hiding, though it has been useful for failovers. We're now considering adding HA within each region, by adding active-passive failovers in using multiple AZs in each region. However, we received an attractive offer from another large IaaS provider to host the failover on their infrastructure at a very competitive price point.

What could be the downside of having a deployment that uses multiple IaaS service providers? There isn't much literature out there from real-world deployments.

I'm using following script from my windows machine to run on linux and do backup.

@ECHO off
:: run remote command
plink.exe username@myserver /home/username/do-backup.sh

Problem with this script is that, i have to keep my session live. as backup takes 30 minutes or so , so I want to know if there is any way I run this script and after that backup command keeps working even if i turn off my system. or you can say that i execute my batch file it goes to server, execute script on server and then comes back while backup script keeps running on server.

Given this folder / file structure:

private/.htpasswd
public/.htaccess

... where public is the root folder of a virtual host in Apache, and private is its sibling folder:

How do I define a relative path for AuthUserFile in the .htaccess file, such that it is able to access /private/.htpasswd

I've tried:

AuthType Basic 
AuthUserFile ../private/.htpasswd
require valid-user

But that doesn't work, because it tries to find the file relative to the ServerRoot, in stead of relative the virtual host root.

I won't have access to the config file on the production server (shared host) and I don't want to define an absolute path, because my testing and production file system structures don't match.

Is it still possible to achieve what I want, given these conditions?

Some of this question would be highly application-specific, but what approaches do you take when looking to migrate applications from one server/platform to another and servers from one network segment to another?

For applications that can't be re-IP'd (many exist in this category), the general answer is to nuke and pave (or extend a clusterable application, then remove the segment that needs to be "moved").

For "normal" applications (httpd, mail, directory services, etc), what are the checks you perform before, during, and after a move to ensure the health of the migrated app/server?

An example with Apache:

1. backup httpd conf directory
2. change httpd conf files to use new IP address of server
3. change (or add) IP of server
4. update DNS entries
5. restart Apache
6. verify web server still serves pages
7. reboot server
8. verify environment comes back up healthy

Virtualization has some great benefits, but there are times when a virtualized server needs more performance and should be moved to physical.

My question is, how do you tell when these times are? I'm looking for measurable data and metrics that show moving a server to its own physical box would make a significant difference to performance. Personally I'm interested in Windows but presumably the essentials are the same across all platforms.