This is the third article in our series on “What’s the Best Choice for Archiving Video?” in the cable, education and healthcare space. We reported in July that Sony discontinued it’s line of AIT Storage products which served as a great archive for users with large video libraries. In September we looked at whether you should consider using DVD as a possible archive source and later looked at whether it makes sense to use external hard drives as an archive. Today we will look at NAS or Network Attached Storage.
Network Attached Storage Overview
Network Attached Storage or NAS is designed to be a separate server attached to your network with it’s own IP address, operating system and storage capacity. Storage is typically in a RAID format so there is some redundancy and one or more spare drives included. The NAS has only one purpose and that is to provide file-based data storage services to other devices on the network. Although it is technically possible to run other software on a NAS unit, it is not designed to be a general purpose server. For example, NAS units usually do not have a keyboard or display, and are controlled and configured over the network only.
In a video environment the NAS is not directly attached to your playback or video on demand server like a SCSI device but instead uses the Local Area Network so it also connects to other video-based systems such as encoders, NLE’s, transcoders and Master Control. This connectivity improves flexibility, productivity and enables automated backup and automated file movement.
Installing a NAS on your network provides several advantages that other storage options do not:
- The NAS is live all the time so anyone with network access has access to files thus improving productivity.
- The NAS is separate from your playback server which provides an extra level of redundancy and ensures your playback server is kept up to date and runs optimally.
- Editors can store work on the NAS rather than on NLE’s which helps avoid accidental file deletion or the creation of orphan files.
- Because the NAS is available to all video devices including the playback server, encoders, transcoders and NLE’s the broadcast automation system can schedule automatic backups as well as file movement to and from the playback server to keep the playlist up to date.
- Storage expansion is easier because you can add additional NAS boxes as you fill up your storage space. This makes it much easier to budget and plan.
What Size NAS is the Right Size?
The best way to estimate your storage needs is to calculate how many hours of new video you process or acquire each week or month and project out a year or more including at least a 20% overhead number to provide a cushion. Check the average size of your typical video program and use that as your guide. If you are currently shopping for a new NAS and your current storage requirement is over 80% of what you are buying I would recommend you buy bigger to ensure you have expansion room.
If money is tight you can purchase a NAS unit without fully populating it with drives and then add additional drives in separate arrays in the future or purchase a small unit and add another later when funds are available.
Is the NAS my Archive as Well?
Should you consider a NAS as your storage archive as well? If you can afford it, I would recommend against this because even though your NAS is RAID it can still have a terminal failure which means you could conceivably lose your content if this happens. The best way to avoid this is to have a redundant NAS that only serves as an archive unit. This gives you additional redundancy that provides further protection. If you refer to the infographic at the top of the page you will note the NAS feeds the front line video components but is backed up by a separate archive device. This is prudent insurance.
In mission critical data centers they will always utilize a separate archive source, usually tape, that is in a different location to ensure protection against all possible disasters. You may also have heard of hierarchical storage where multiple levels of storage are maintained in different formats, usually fast (expensive) for quick access and slow (inexpensive) for data that is not accessed as often.
If you don’t have the funds to purchase a second NAS to use as an archive you can make do with one unit but it is very important that you check the status of all drives in the system on a regular basis, replace bad drives quickly when they die and keep the NAS unit clean and dust free.
For more information on storage and how to protect your video asset please download our free e-paper: A Guide to Video Storage.