Digital preservation is about maintaining access to digital files over (long periods of) time, whereas digital storage is about keeping the digital items themselves.
Though digital preservation includes storage of digital items (keeping the 1s and 0s that make up digital files) safe and sound, there is more than to it than that.
In the same way that we look after our hardcopy heritage items, we need to keep the 1s and 0s of digital heritage items in the best conditions. Following (IT) industry standard, we back up our files in multiple physical locations, on different media, and make regular backups of our content. Doing this minimises the risk of any issues occurring (e.g. a physical disaster like a fire), and ensuring copies of our data are on different media helps protect against issues related to specific hardware (e.g. a bad batch of discs, or a certain type of backup tape becoming obsolete).
Floppy disc drives – examples of obsolete hardware
For digital preservation purposes, when we receive a digital file, we take note of how it came to us. We look at what type of content it is (a text file, an image, a sound recording), as well as what file type it is (.doc, .jpeg, .mp3), and what type of software is needed to open or view the file. These pieces of information help us to know what to do with the file, and also what type of risks this file may be exposed to.
File types can be considered at risk because of a number of reasons – the company that created the file type may abandon support of the program needed to open the file, or upgrades to software may result in older files becoming inaccessible. In DigitalLand, it’s very likely that certain files are only supported on certain computer operating systems, and sometimes those operating systems are hard to come by (Windows version 3.1 anyone?).
When we receive files, we keep an exact copy of what we have received, as well as making a copy of the file in an open format (i.e. a format that can be used by anyone). We also create versions of the file (derivatives) for delivery over the web. Luckily for us, most of this processing happens automatically, so it’s not a matter of a person opening a file and saving lots of different versions of that file, which frees us up to collect even more files!
Even once we have made the different copies, and are confident that our backups are secure, our job is not yet over; as we need to stay tuned for changes that may mean that we need to migrate our files into new(er) formats, so we can continue to offer access to the files using current technology. We are regularly are seeing new file types emerge (e.g. 360 degree video), and are seeing many more digital files coming to us, as more and more people turn to digital methods to capture and re-tell their stories.
In terms of storage, to protect your own digital files, here are some steps you can take;
- Make sure you know where your files are (many of us have files in different places – e.g. some files on a laptop, some on a mobile phone and others on an external hard disc)
- Consolidate and make more than one copy of the files – copy all your files to one location, then make backups from that place to other media. Many people now have access to online (web) storage, as well as traditional media such as discs.
- Ensure you have the environment (software/hardware) that you need to open the file, and that you have all the peripherals you need (do you know where that cable or power supply you need to connect that hard drive is?). Where you need special software to open the file, and that software is ageing, can you save it to a modern format?
- Migrate the content to new media regularly – every couple of years, replace the media you are using to back up your digital files. Though media is generally stable for a few years, the risk to losing data off this media increases with every year that passes
The storage array at the State Library