Imagery can be stored, and served, from anywhere on your network.
You do need to be aware of some simple network and security considerations.
Just like you "login" to your computer, so does the applications that you use. Sometimes they just "borrow" your login, but other times they use any number of system defined "user details". This is particularly the case for any server application.
Image Web Server operates under a defined user account. This account must have “read” access to the image files in order to serve them. If IWS can read the imagery, it can serve the imagery. If it can't read the imagery, obviously, it can't serve the imagery to anyone.
The default user account that IWS runs under is the same account that Internet Information Services uses to authorize “anonymous requests”.
To explain this, when you visit any website, you are viewing "files" from that website. In order to view these files you need "permission". But, most times, you don't have to enter a user name or anything, you just get to see the information. This is where the idea of an "anonymous user" account comes in. Even though everyone should be able to access the information, Windows still needs to validate and secure the information. So, what IIS does, is give windows the user credentials of this anonymous account, when any user (an anonymous user) requests information that should be available to everyone.
The account name is that is used for this "anonymous access" is called IUSR_<machinename>. So, in my instance, my computer is called "Willow", so the default account listed in my IIS is IUSR_WILLOW.
The IUSR account is local to the machine. It is not attached to an external network or domain. It can only access resources that are local to the machine (e.g. it’s C: drive, or another local drive, etc).
If your imagery is stored on your local machine, this local IUSR account will be sufficient. It is important to remember that the local account IUSR_<machinename> does not have access to all the drives or areas of your discs. If after adding Imagery to IWS the image does not display in the console (you get an 'x' next to the image in the file list), it is likely that the user account doesn’t have “read” permission for this area on your hard discs. To rectify this, simply change the properties to the hard disc area to allow this user account to “read” the imagery.
Storing imagery on another server or external storage device
In order to be able to access imagery from another computer, IWS must operate under an account that has read access to the imagery. Typically, you would create a new “user” on the network that has read permissions for the imagery, as well as the same permissions as the IUSR_<machinename> account. As you know, the default user account only has “local” access. It cannot view anything that is not part of its physical machine.
Once the account has been created and tested, you then update the Internet Information Services “anonymous user” account with this new users details into Internet Information Services Directory Security.
- Open up IIS Admin console.
- Right click on the website with IWS attached to it.
- Select the “directory security” tab
- Edit the “anonymous access”
- Add your new network domain user name and password.
Please ensure that your IWS has fast access to the imagery to ensure optimal performance. For example, other network traffic could interfere with “access time”, etc, and thus reduce the speed of your imagery servicing.
This process is explained more fully in the IWS User Guide, in the section titled “Image Files on a Remote
Windows Server or NAS”.