In my last post I mentioned the soft launch of the public front end of our Preservica system, Universal Access, and discussed briefly more long-term goals to improve access to our digital collections.
A few recent developments have occurred in relation to our digital preservation work, including the publication of our Digital Preservation Policy. These are detailed below.
The Digital Preservation Policy
The National Archives defines a Digital Preservation Policy as ‘the mandate for an archive to support the preservation of digital records through a structured and managed digital preservation strategy.’
We have revised and shortened our own policy and a copy is now available for consultation here.
As is true for physical archives, in the case of digital archiving preservation and access are two sides of the same coin. The Access chapter in the Digital Preservation Coalition’s Handbook states:
Preserving access to digital objectives is the key objective of digital preservation programmes but requires more active management throughout the lifecycle of the resource before it can be assured
There is little point in preserving digital records if a collecting repository lacks the infrastructure or intention to at least begin making their digital assets accessible. Various elements of bitstream and lifecycle preservation which help guarantee long-term survival of digital assets have been discussed in previous posts.
This post looks less at more general theoretical and practical aspects of digital preservation and access, and instead looks at some steps I am taking to improve remote access to our digital collections, particularly “born-digital” resources.
Preservica and Access
Over the past two years I have been developing our Preservica digital preservation repository system – around two terabytes of content are now actively managed within the system. Workflows and processes are in place to monitor, integrity check and perform necessary preservation actions, helping guarantee long-term survival of, and therefore access to our digital resources.
Recently, it was decided to soft launch the public front end of our Preservica system. Based on WordPress, Universal Access comprises the user side of the platform. Content is given one of three security tags – “closed”, “open” and “public”. Anything “public” becomes visible and technically discoverable online.
Birmingham Archives and Collections Preservica UA Homepage
Universal Access – where is it, what’s on it?
Our Universal Access page can be found at https://birmingham.access.preservica.com/. You can browse various broad collection types by clicking the link buttons or conduct a basic search of the digital repository. Search functionality is currently limited as we are making a deliberately select batch of content live to begin with, pending feedback and further site development.
In my last post I (hopefully) provided a succinct introduction to digital preservation, what it is and why it’s important. This post looks at an activity fundamental to digital preservation– Bitstream Preservation. To understand its importance, it’s useful to think about your own experiences of using digital files, particularly something awful that occurred which brought these issues sharply into focus.
Data loss – risks and solutions
A long time back an external hard drive with all my digital photos became corrupted, the data irretrievably lost! The laptop was old with very limited storage – I moved (rather than copied) my photos onto a clunky external hard drive to free up space. I had no cloud storage then – I naively thought having one copy on external drive would be enough!
Photography is a hobby of mine. Losing all my work was highly annoying, and I resolved this would never happen again. To mitigate against future disasters, I took the following steps:
Upgraded my laptop to a higher spec model with 500 GB of memory – not much nowadays days (the laptop is a decade old) but way better than what I had before!
Purchased cloud storage, regularly copying new and updated digital files across
Regularly copy digital files across onto new 1 TB external storage drive
Retain all SD cards once full, storing them in a water-resistant storage case – a tip suggested to us by a tutor on a photography course I attended two years ago.
Check external storage media to make sure it hasn’t been corrupted – if so, I replace it, copying lost files across from another storage device
This of course required expenditure, but I now have FOUR copies of my files on live and static storage media, kept in different locations should one of the above methods fail.
Digital preservation at home. Clockwise, top left…laptop with Dropbox, external drive, Canon DSLR camera, 32 GB memory card.
Bitstream Preservation explained
Without realising, I was in fact doing a form of digital preservation at its most basic level. Practitioners refer to this as Bitstream or Passive Preservation. The Bodleian Library website defines it as ‘literally preservation of the bits of a digital object’ – in other words, the 1’s and 0’s (or Bytes) described in my last post.
The process entails ‘maintaining onsite and offsite backup copies, as well as virus checking, fixity-checking, and periodic refreshment to new storage media’, and denotes a relatively low intervention approach. Files are stored and regularly backed up across geographic locations, checked every so often to make sure the files have not become corrupted, storage media regularly refreshed. Corrupted or damaged files are replaced with (hopefully) uncorrupted master copies from another storage location, as identified.
Many of these things you may already do – except possibly Fixity Checking which I’ll look at in a future post. Unfortunately, simply preserving copies of the original file unaltered is not enough to reduce the risk of it becoming unreadable. Hardware, software and file format obsolescence could still render a robust, perfectly preserved digital file inaccessible and unreadable on future generations of technology. Bitstream or passive preservation is best seen as a key building block underpinning the more integrated series of managed processes known as Active Preservation, which ensures that files can be managed, understood and accessed as a result of these technological changes.
Historical photos of Acocks Green with corresponding XML metadata files and documentation folder, prepared for test ingest into Preservica digital Repository System
Concluding remarks…and a quick word about file formats
Hopefully this helps demystify a fundamental aspect of digital preservation work – it may even reassure you to know you are in fact doing an elementary form of digital preservation, and managing your files robustly going into the future!
There is always a trade-off, storage requirements and the robustness and effectiveness of the various processes balanced against storage costs. Issues like these are magnified for larger organisations who require digital records to be retained for many decades for reasons of financial, statutory or legal accountability, or archive services preserving historical records in perpetuity in accordance to a predefined collecting policy.
On a related matter, you may want to also consider the file formats in which you create and store your digital information. Formats like RAW or TIFF are technically lossless and make ideal preservation copies – but at around three times the size of equivalent JPEGs, they eat up disk space! In terms of home use, file formats were not things I’d given much thought until more recently. I intend to look at these in more detail in the next post…
The technical buzzwords!
The various bits of terminology I’m gradually introducing in italics, hopefully explaining things as I go! The lingo is better explained in various technical glossaries online, some good places to look include:
My name is Mike Hunkin and I am the new Digital Preservation Officer at the Library of Birmingham, currently employed on a fixed-term contract until October 2022. I am currently based in Archives and Collections, having worked here for just under nine years between 2006 and 2015. This is a bit of a new area for me, my area of work now focusing on developing systems to ensure the long-term preservation of digital archives and assets held across our library and archive collections.
What is digital preservation?
Managing digital collections is no different to looking after more traditional paper archives in terms of outcome – preservation and access to recorded information remain both sides of the same coin. It is the complex and rapidly changing technological environment in which digital objects exist that presents a fundamental challenge to their long-term survival.
The Bitstream, from Microsoft Office Clip Art
Digital records are inherently unstable. Built from a series of seemingly random binary 1s or 0s (digital bits, or bytes), they are reliant upon a complex series of digital interactions between storage media, software and/or hardware to ensure they can be read. A damaged disk or a series of missing bytes can render a digital item or set of files permanently and irretrievably lost.
In this context the Digital Preservation Coalition defines digital preservation as:
‘the series of managed activities necessary to ensure continued access to digital materials for as long as necessary…and refers to all of the actions required to maintain access to digital materials beyond the limits of media failure or technological and organisational change.’Continue reading “Digital Preservation at the Library of Birmingham – an introduction”→
The Iron Room 