I have a shared drive on the network willing to expose to sharepoint so the users will be able to searcch its content from sharepoint.
In case you want / need to provide a different account to crawl this share you can specify one within the Crawl Rules (Search Service Application > Crawl Rules)
Make sure that the permissions within the share and all of its (sub-)folders are correct since indexing a file share can make it much easier for people to find files that they normally don't have access to.
If the user can access the SHARE and Folder C but not Folder A and Folder B he/she normally can't access files in Folder C without knowing the exact path. Once indexed in SharePoint it is an easy thing to find files from Folder C. (I hope that was somewhat understandable - English isn't my 1st language)
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