In his article, What NOT to migrate into SharePoint Joel identifies the usual suspects of types of files which are not suited to be stored in SharePoint or any DMS system for that matter.
While Joel covers the what quite exquisitely, he does not cover the why from an IA point of view. I have seen companies throw hundred thousands of dollars at setting up SharePoint farms to store ALL their documents. Including massive investments in infrastructure and likewise projects required to design a stable and usable system with minimal change impact to the end users. But what they all forget to ask is the big WHY? Why migrate the content? Where is the business value? The standard answers you will get most of the time will go along the lines of “because with SharePoint we can manage the files better” “We then have versioning” “One central platform instead of disparate locations”. And that is when the headache begins. Dead documents are brought to life in SharePoint only for the sake of having one single source of truth. These zombie documents devour resources and money the instant they are resurrected and cause major maintenance headaches for all involved.
When the team of BAs and IAs are classifying all the documents they often skip the most important classification. Is this document still active or is it at the end of its life? Will there be any form of collaboration going on or will it only be used as reference material. If you can make that distinction you will easily be able to identify exactly which files need to move into a managed environment and which can stay in an unmanaged location. Many projects shy away from this question simply because it can be a daunting task. There might be millions of documents that need to be classified into active and non active. Also there is the problem of having separate locations for associated documents. This is where third party providers can come in extremely handy. While some offer Web Parts which will display existing file shares in SharePoint in a more integrated manner, they will lack the full functionality support of a SharePoint document library. So if you do not need versioning or SharePoint driven security, then have a look for Network Share Web Parts on http://www.sharepointreviews.com/ There are some web parts listed there.
If you on the other hand want to have versioning, SharePoint driven security, Check-in and out, then more complex solutions will be needed. Such as the File Share Library by bamboo solutions which synchronises a fileshare with a document library. The only downside is that files will start clogging up the database once they move from stale to active use. This way at least the databases will grow gradually over time as more and more documents are activated. The final solution I want to suggest is using the FileShare connector from AvePoint. They have designed a solution based on their popular EBS driven Storage Extender which keeps the file share separate from the database even once files are actively used and versioned in SharePoint. The magic lies in a hidden folder on the fileshare which is used to maintain the new versions of the files, as they progress through the lifecycle.
But beware! Only because the DBA need not worry about 5TB big content databases no more means nobody should. A well planned major and minor versioning strategy and user education is key in keeping the network storage from blowing out of proportions. So do yourself a favour and have a look at some tools on the market before needlessly resurrecting dead documents into SharePoint.