How to configure SharePoint 2010 Search to crawl file servers?
SharePoint 2010 allows you to setup a search documents in file Share. Flowing steps will guide you to setup SharePoint 2010 search to access network file share
1. Go to Central Administration Search Service Application: Manage Content Sources 
2. Use this page to add, edit, or delete content sources, and to manage crawls. Click on New Content Source
Name
Type a name to describe this content source.
Content Source Type
Select what type of content will be crawled.
Note: This cannot be changed after this content source is created because other settings depend on it.
Start Addresses
Type the URLs from which the search system should start crawling.
This includes all SharePoint Server sites and Microsoft SharePoint Foundation sites.
Crawl Settings
Specify the behavior for crawling this type of content.
Selecting to crawl everything under the hostname will also crawl all the SharePoint Sites in the server.
Caution: After you select crawl settings for a SharePoint content source, you cannot change crawling behavior unless you re-create the content source. Verify that you select the option that best suits your needs
Crawl Schedules
Select the crawl schedules for this content source.
Start Full Crawl
Select "Start full crawl of this content source" and click "OK" to start a full crawl of this content source.
Click Ok to perform a full crawl of this content source
3. Let’s go and create Search Scopes for External File Share
Use this page to view and manage search scopes. The order in which the search scopes appear in this list is the order in which they will appear in the search scope list next to the Search box.
Central Administration Search Service Application: View Scopes
Add your scopes and click OK
4. Now click on your new scope which you created and add rules
Scope Rule Type
Scope rules define what is in or not in a scope. Use different types of rules to match items in various ways
Web Address
Web Address scope rules can be used to create search scopes that include content in web sites, the shares, exchange public folders, or any other content in the search index that has a URL.
Folder rules will include items in the folder and subfolders of the indicated path.
Domain or hostname rules include all items within the specified domain or hostname.
Behavior
Decide how this rule should be applied to the overall scope. The scope-wide filter is used when combining the items matching all rules to determine what is in the scopes overall.
Select Content Source and from the drop down list select File Share
Step 2 : Create a SharePoint Enterprise Search Center
1. Go to Central Administration | Application Management | Create Site Collection
Select Enterprise search center template to create Search Center
2. Copy your new Search Center URL and go to your SharePoint Site
The new top-level site was created successfully with the specified URL. If you have permission to view the Web site, you can do so in a new browser window by clicking the URL. To return to SharePoint Central Administration, click OK .
Site Actions | Site Settings | Site Collection Administration | Search Settings
Past your Search Center URL and Enable Custom Scopes
Site Collection Search Center
To enable sites to search custom scopes (such as "All Sites"), you must define a Search Center URL.
Once enabled, Search Boxes will show custom scopes to the user in the scopes dropdown. Custom scopes can be defined in either this Site Collection or the Search Service scopes pages. Queries will be sent to the Search Center URL with the scope’s results page appended.
By checking the "Use site level defaults" web part property, the search box will send custom scope queries to the Search Center defined in this "Site Collection Search Center" property.
Site Collection Search Dropdown Mode
Use this setting to configure the dropdown mode for search boxes in this site collection. The dropdown can include Contextual or Custom Scopes. The dropdown can show in the interface, or it can not show and simply direct searches to a default scope.
By default, a Search Box will use the "Dropdown Mode" property in the web part. By checking the "Use site dropdown mode" property, the search box will use this "Site Collection Search Dropdown Mode" setting instead.
Site Collection Search Results Page
Use this setting to configure the search results page used for contextual searches (such as "This Site"). This page will not be used for custom scopes.
By default, a Search Box will use the "Target Results Page" property in the web part. By checking the "Use site level defaults" property, the search box will use this "Site Collection Target Results Page" setting instead.
Step 3 : Create a SharePoint Enterprise Search Center
Site Actions | Site Settings | Site Collection Administration | Search Settings | Search Scopes
Under unused scopes you can see File Share. Now click on Display Groups
Click on Search Dropdown
Select your File Share
Scopes in this group will appear with the search box in the scopes dropdown.
This will enable File Share in Search dropdown and allow you to search files with in the shared folder.
I had to restart IIS to see this
Let’s go and search some files in the File Share folder. These are the files which I have in the Shared Folder
I am going to search “ ERP Data”
Results: All the files are coming from my Shared Folder.
