Obsolescence

VHS – more obsolescence threats

S-VHS-Machine-Great-Bear-Analogue-Digital-Media

Earlier this month we wrote an article that re-appraised the question of VHS obsolescence.

Variability within the VHS format, such as recording speeds and the different playback capacities of domestic and professional machines, fundamentally challenge claims that VHS is immune from obsolescence threats which affect other, less ubiquitous formats.

The points we raised in this article and in others on the Great Bear tape blog are only heightened by news that domestic VHS manufacture is to be abandoned this month.

It is always worth being a bit wary of media rhetoric: this is not the first time VHS’s ‘death’ has been declared.

In 2008, for example, JVC announced they would no longer manufacture standalone VHS machines.

Yet Funai Electric’s announcement seems decidedly more grave, given that ‘declining sales, plus a difficulty in obtaining the necessary parts’ are the key reasons cited for their decision.

To be plain here: If manufacturers are struggling to find parts for obsolete machines this doesn’t bode well for the rest of us.

The ‘death’ of a format is never immediate. In reality it is a stage by stage process, marked by significant milestones.

The announcement last week is certainly one milestone we should take notice of.

Especially when there are several other issues that compromise the possibility of effective VHS preservation in the immediate and long term future.

What needs to be done?

As ever, careful assessment of your tape collection is recommended. We are always on hand to talk through any questions you have.

Posted by debra in video tape, video technology, machines, equipment, 0 comments

VHS – Re-appraising Obsolescence

VHS was a hugely successful video format from the late 1970s to early 2000s. It was adopted widely in domestic and professional contexts.

Due to its familiarity and apparent ubiquity you might imagine it is easy to preserve VHS.

Well, think again.

VHS is generally considered to be a low preservation risk because playback equipment is still (just about) available.

There is, however, a huge degree of variation within VHS. This is even before we consider improvements to the format, such as S-VHS (1987), which increased luminance bandwidth and picture quality.

Complicating the preservation picture

The biggest variation within VHS is of recording speed.

Recording speed affects the quality of the recording. It also dictates which machines you can use to play back VHS tapes.

2 large, light-coloured professional video machines with digital counters, needle gauges and multiple dials

SONY SVO-500P and Panasonic AG-650

Domestic VHS could record at three different speeds: Standard Play, which yielded the best quality recordings; Long Play, which doubled recording time but compromised the quality of the recording; Extended or Super Long Play, which trebled recording time but significantly reduced the recording quality. Extended/ Super Long Play was only available on the NTSC standard.

It is generally recognised that you should always use the best quality machines at your disposal to preserve magnetic media.

VHS machines built for domestic use, and the more robust, industrial models vary significantly in quality.

Richard Bennette in The Videomaker wrote (1995): ‘In more expensive VCRs, especially industrial models, the transports use thicker and heavier mounting plates, posts and gears. This helps maintain the ever-critical tape signal distances over many more hours of usage. An inexpensive transport can warp or bend, causing time base errors in the video signals’.

Yet better quality VHS machines, such as the Sony SVO-5800P and Panasonic AG-8700 that we use in the Greatbear Studio, cannot play back Long or Extended Play recordings. They only recorded—and therefore can only play back—Standard Play signals.

This means that recordings made at slower speeds can only be transferred using domestic VHS machines, such as the JVC HM-DR10000 D-VHS or the JVC HR-DVS3 EK.

Domestic VHS tape: significant problems to come

This poses two significant problems within a preservation context.

Firstly, there is concern about the availability of high-functioning domestic VHS machines in the immediate and long-term.

Domestic VHS machines were designed to be mass produced and affordable to the everyday consumer. Parts were made from cheaper materials. They simply were not built to last.

JVC stopped manufacturing standalone VHS machines in 2008.

Used VHS machines are still available. Given the comparative fragility of domestic machines, the ubiquity of the VHS format—especially in its domestic variation—is largely an illusion.

The second problem is the quality of the original Long or Extended Play recording.

silver and black slimline VHS machine

JVC Super-VHS ET

One reason for VHS’s victory over Betamax in the ‘videotape format wars’ was that VHS could record for three hours, compared with Betamax’s one.

As with all media recorded on magnetic tape, slower recording speeds produce poorer quality video and audio.

An Extended Play recording made on a domestic VHS is already in a compromised position, even before you put it in the tape machine and press ‘play.’

Which leads us to a further and significant problem: the ‘press play’ moment.

Interchangeability—the ability to play back a tape on a machine different to the one it was recorded on—is a massive problem with video tape machines in general.

The tape transport is a sensitive mechanism and can be easily knocked out of sync. If the initial recording was made with a mis-aligned machine it is not certain to play back on another, differently aligned machine. Slow recording complicates alignment further, as there is more room for error in the recording process.

The preservation of Long and Extended Play VHS recordings is therefore fraught with challenges that are not always immediately apparent.

(Re)appraising VHS

Aesthetically, VHS continues to be celebrated in art circles for its rendering of the ‘poor image’. The decaying, unstable appearance of the VHS signal is a direct result of extended recording times that threaten its practical ability to endure.

Variation of recording time is the key point of distinction within the VHS format. It dramatically affects the quality of the original recording and dictates the equipment a tape can be played back on. With this in mind, we need to distinguish between standard, long and extended play VHS recordings when appraising collections, rather than assuming ‘VHS’ covers everything.

One big stumbling block is that you cannot tell the recording speed by looking at the tape itself. There may be metadata that can indicate this, or help you make an educated guess, but this is not always available.

We recommend, therefore, to not assume VHS—and other formats that straddle the domestic/ professional divide such as DVCAM and 8mm video—is ‘safe’ from impending obsolescence. Despite the apparent availability and familiarity of VHS, the picture in reality is far more complex and nuanced.

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As ever, Greatbear are more than happy to discuss specific issues affecting your collection.

Get in touch with us to explore how we can work together.

Posted by debra in digitisation expertise, video tape, 1 comment

Guest post: Refurbishment of Magnetic Recording Heads – Terry Summers

Below is a guest post written by Terry Summers from Summertone Ltd. We first encountered Terry because of his expertise refurbishing analogue magnetic tape heads.

As one of the few, if not only, specialist UK-based company working in this area, we wanted to know more about Terry’s work. We were keen to understand the secrets of magnetic tape refurbishment, and whether Terry accepted that obsolescence for analogue media was imminent, as many audiovisual archivists claim. Many thanks Terry for taking the time to write the article, we hope you enjoy it.

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a gap inspection being carried out on an Ampex, half inch, two track, stereo replay head.

a gap inspection being carried out on an Ampex, half inch, two track, stereo replay head

Before I opened Summertone Ltd. I was for very many years, the Managing Director and magnetic head designer for the head manufacturing company Branch & Appleby. This was a specialist company serving the audio recording industry with magnetic heads as a supplier to Original Equipment Manufacturers in the analogue tape and film industry and for replacement heads for other types. B & A was particularly strong in the magnetic head supply for recording on perforated film for the synchronisation and editing of film sound, being the supplier of heads to many OEM studio film equipment manufacturers. The range of analogue heads designed and made by B & A was legion, ranging from 32 track 2 inch to 8mm film heads. B & A also supplied heads for other purposes, magnetic card readers and bank note verifiers being examples.

To be able to refurbish a magnetic head, it is essential to understand the working, the manufacturing principals and the materials used in it’s manufacture.

That expertise is with Summertone and is the reason for its success. The various magnetic materials used (mumetals of various grades, vitrovacs, ferrites etc.) each require specialist equipment and methods of surface finish to obtain intimate contact with the recording medium. A fact that is frequently overlooked is that a refurbished magnetic head has a performance that is superior to when it was new! The reason is that the magnetic losses due to the gap depth are less. So refurbishment not only restores the head’s ability to contact the magnetic material correctly, having removed the uneven wear caused by the abrasive recording medium, but also gives the head an improved performance, essential for the reproduction of archive, sometimes damaged material.

Digital Changes

The audio industry has of course changed with the coming of the digital age, some say for the better, but others disagree. We refurbish analogue heads for studios and individuals that are dedicated to the recording and reproduction of sound with the full complement of all the harmonics that are lost with a digital frequency cut off. We cannot hear them, but they colour the overall sound picture that we hear. That is the reason for the continuation of the use and restoration of the abundance of analogue machines by our studio customers (and some private users also).

The magnetic head is the vital link with the medium and is essential that it is kept in tip-top condition.

There are also many archival organisations that require the services of head specialists. The British Film Institute for instance, prides itself with the fact that the preserved sound it achieves is in many cases superior to the original public performances. This is due to their keeping their magnetic/optical sound pickups in excellent order and then, after transfer, using modern digital techniques to manipulate and store the results. Summertone receives heads from all over the world for refurbishment and is proud and pleased to say that the percentage of heads that it receives for refurbishment that are not able to receive suitable treatment, is very small indeed.

The scarcity of machines can be a problem, but as the number of studios using analogue machines diminishes they tend to pass to dedicated companies and individuals who appreciate their importance and who go to great lengths to ensure they are kept in a working condition or used for spares, not thrown in the skip. We appreciate that this cannot go on for ever, but the indications at the present time are that there are many who have the expertise to help in the specialist areas needed to keep archive machines in good working order.

It is a fact that the older analogue machines seem to be so well designed and built that they have very few faults that cannot be rectified easily. For instance, last week we switched on a 1960s valve recorder that had not been run for very many years. It performed perfectly. Another just needed a simple capacitor replacement for it to also perform. The point we are making is that the older technology was, and still is, reliable and understandable, unlike many modern machines.

It is possible to build new tape head blocks from scratch, but that is really not economical due to cost. We can, and do, still have replacement heads made to my designs but only if it is justified to keep a valuable, scarce, rare format, machines functioning. There are heads around, both new and second hand that can be refurbished. These can be obtained by combining two machines both for mechanical parts and heads. Summertone also has a small stock of heads.

Obsolescence

I do not agree with the archivists who say that there is a 10-15 year span left to transfer material. Magnetic tape and film has stood the test of longevity without deterioration which is why it is still being used for digital archiving. More modern archive methods have been failing. With good maintenance, analogue machines have a good life left and spares are still able to be obtained and manufactured as they are understandable to good engineers. I am sorry to say that when Summertone closes, our expertise for magnetic heads will be lost as it has not been possible to transfer a lifetime of analogue experience to another, due partly to the lack of financial incentive.

Posted by debra in audio tape, audio technology, machines, equipment, 2 comments

Save Our Sounds’ £9.5 million boost

british-library-sound-archivesThis article is a bit late to break this news, but it is worth highlighting again in case you missed it first time round.

In May 2015 the British Library were awarded over £9.5 million pounds by the Heritage Lottery Fund to help them deliver their hugely important Save Our Sounds project.

We told you about Save Our Sounds earlier in the year.

As stated in a press release, ‘the funding will enable the British Library to digitise and make available 500,000 rare, unique and at-risk sound recordings from its own archive and other key collections around the country over 5 years (2017-2022).’

Funding will also help ‘develop a national preservation network via ten regional centres of archival excellence which will digitise, preserve and share the unique audio heritage found in their local area.’

Living Knowledge

Also worth a read is the recently published Living Knowledge: The British Library 2015-2023, which sets out the strategic priorities of the organisation in its 50th anniversary year.

The short text outlines ‘what it means to be a national library in a digital age and what the British Library’s role is as one of the UK’s great public assets.’

These are set out in ‘a framework of six purposes which explain, as simply and clearly as we can, the enduring ways in which the public funding we receive helps to deliver tangible public value – in custodianship, research, business, culture, learning and international partnership.’

Within the strategy digitising ‘the 42 different physical formats which hold our 6.5 million audio items’ is highlighted as ‘the next great preservation challenge’ for the British Library.

As ever, we will keep you up to date with updates from the British Library’s Save Our Sounds project as it evolves.

Posted by debra in audio / video heritage, audio tape, 0 comments

World Day for Audiovisual Heritage – digitisation and digital preservation policy and research

Today, October 27, has been declared World Day for Audiovisual Heritage by UNESCO. We also blogged about it last year.

Since 2005, UNESCO have used the landmark to highlight the importance of audiovisual archives to ‘our common heritage’ which  contain ‘the primary records of the 20th and 21st centuries.’ Increasingly, however, the day is used to highlight how audio and moving image archives are particularly threatened with by ‘neglect, natural decay to technological obsolescence, as well as deliberate destruction’.

Indeed, the theme for 2014 is ‘Archives at Risk: Much More to Do.’ The Swiss National Sound Archives have made this rather dramatic short film to promote awareness of the imminent threat to audiovisual formats, which is echoed by UNESCO’s insistence that ‘all of the world’s audiovisual heritage is endangered.’

As it is World Audiovisual Heritage Day, we thought it would be a good idea to take a look at some of the recent research and policy that has been collected and published relating to digitisation and digital preservation.

While the UNESCO anniversary is useful for raising awareness of the fragility of audiovisual mediums, what is the situation for organisations and institutions grappling with these challenges in practice?

Recent published research – NDSA

The first to consider are preliminary results from a survey published by the US-based NDSA Standards and Practices Working Group, full details can be accessed here.

The survey asked a range of organisations, institutions and collections to rank issues that are critical for the preservation of video collections. Respondents ‘identified the top three stumbling blocks in preserving video as:

  • Getting funding and other resources to start preserving video (18%)
  • Supporting appropriate digital storage to accommodate large and complex video files (14%)
  • Locating trustworthy technical guidance on video file formats including standards and best practices (11%)’

Interestingly in relation to the work we do at Great Bear, which often reveal the fragilities of digital recordings made on magnetic tape, ‘respondents report that analog/physical media is the most challenging type of video (73%) followed by born digital (42%) and digital on physical media (34%).’

It may well be that there is simply more video on analogue/ physical media than other mediums which can account for the higher response, and that archives are yet to grapple with the archival problem of digital video stored on physical mediums such as DVD and in particular, consumer grade DVD-Rs. Full details will be published on The Signal, the Library of Congress’ Digital Preservation blog, in due course.

Recent research – Digital Preservation Coalition (DPC)

Another piece of preliminary research published recently was the user consultation for the 2nd edition of the Digital Preservation Coalition’s Digital Preservation Handbook. The first edition of the Handbook was published in 2000 but was regularly updated throughout the 00s. The consultation precedes what will be a fairly substantial overhaul of the resource.

Many respondents to the consultation welcomed that a new edition would be published, stating that much content is now ‘somewhat outdated’ given the rapid change that characterises digital preservation as a technological and professional field.

Survey respondents ranked storage and preservation (1), standards and best practices (2) and metadata and documentation (3) as the biggest challenges involved in digital preservation, and therefore converge with the NDSA findings. It must be stressed, however, that there wasn’t a massive difference across all the categories that included issues such as compression and encryption, access and creating digital materials.

Some of the responses ranged from the pragmatic…

‘digital preservation training etc tend to focus on technical solutions, tools and standards. The wider issues need to be stressed – the business case, the risks, significant properties’ (16)

‘increasingly archives are being approached by community archive groups looking for ways in which to create a digital archive. Some guidance on how archive services can respond effectively and the issues and challenges that must be considered in doing so would be very welcome’ (16)

…to the dramatic…

‘The Cloud is a lethal method of storing anything other than in Lo Res for Access, and the legality of Government access to items stored on The Cloud should make Curators very scared of it. Most digital curators have very little comprehension of the effect of solar flares on digital collections if they were hit by one. In the same way that presently part of the new method of “warfare” is economic hacking and attacks on financial institutions, the risks of cyber attacks on a country’s cultural heritage should be something of massive concern, as little could demoralise a population more rapidly. Large archives seem aware of this, but not many smaller ones that lack the skill to protect themselves’ (17)

…Others stressed legal issues related to rights management…

‘recording the rights to use digital content and ownership of digital content throughout its history/ life is critical. Because of the efforts to share bits of data and the ease of doing so (linked data, Europeana, commercial deals, the poaching of lines of code to be used in various tools/ services/ products etc.) this is increasingly important.’ (17)

It will be fascinating to see how the consultation are further contextualised and placed next to examples of best practice, case studies and innovative technological approaches within the fully revised 2nd edition of the Handbook.

European Parliament Policy on Film Heritage

Our final example relates to the European Parliament and Council Recommendation on Film Heritage. The Recommendation was first decreed in 2005. It invited Member States to offer progress reports every two years about the protection of and access to European film heritage. The 4th implementation report was published on 2 October 2014 and can be read in full here.

The language of the recommendation very much echoes the rationale laid out by UNESCO for establishing World Audiovisual Heritage Day, discussed above:

‘Cinematography is an art form contained on a fragile medium, which therefore requires positive action from the public authorities to ensure its preservation. Cinematographic works are an essential component of our cultural heritage and therefore merit full protection.’

Although the recommendation relates to preservation of cinematic works specifically, the implementation report offers wide ranging insight into the uneven ways ‘the digital revolution’ has affected different countries, at the level of film production/ consumption, archiving and preservation.

The report gravely states that ‘European film heritage risks missing the digital train,‘ a phrase that welcomes a bit more explanation. One way to understand is that it describes how countries, but also Europe as a geo-political space, is currently failing to capitalise on what digital technologies can offer culturally, but also economically.

The report reveals that the theoretical promise of interoperable digital technologies-smooth trading, transmission and distribution across economic, technical and cultural borders-was hindered in practice due to costly and complex copyright laws that make the cross border availability of film heritage, re-use (or ‘mash-up’) and online access difficult to implement. This means that EU member states are not able to monetise their assets or share their cultural worth. Furthermore, this is further emphasised by the fact that ‘85% of Europe’s film heritage is estimated to be out-of-commerce, and therefore, invisible for the European citizen’ (37).

In an age of biting austerity, the report makes very clear that there simply aren’t enough funds to implement robust digitization and digital preservation plans: ‘Financial and human resources devoted to film heritage have generally remained at the same level or have been reduced. The economic situation has indeed pushed Member States to change their priorities’ (38).

There is also the issue of preserving analogue expertise: ‘many private analogue laboratories have closed down following the definitive switch of the industry to digital. This raises the question on how to maintain technology and know-how related to analogue film’ (13).

Production Heritage Budget EUThe report gestures toward what is likely to be a splitting archival-headache-to-come for custodians of born digital films: ‘resources devoted to film heritage […] continue to represent a very small fraction of resources allocated to funding of new film productions by all Member States’ (38). Or, to put it in numerical terms, for every €97 invested by the public sector in the creation of new films, only €3 go to the preservation and digitisation of these films. Some countries, namely Greece and Ireland, are yet to make plans to collect contemporary digital cinema (see opposite infographic).

Keeping up to date

It is extremely useful to have access to the research featured in this article. Consulting these different resources helps us to understand the nuts and bolts of technical practices, but also how different parts of the world are unevenly responding to digitisation. If the clock is ticking to preserve audiovisual heritage in the abrupt manner presented in the Swiss National Archives Film, the EU research in particular indicates that it may well be too late already to preserve a significant proportion of audiovisual archives that we can currently listen to and watch.

As we have explored at other places in this blog, wanting to preserve everything is in many ways unrealistic; making clinical selection decisions is a necessary part of the archival process. The situation facing analogue audiovisual heritage is however both novel and unprecedented in archival history: the threat of catastrophic drop out in ten-fifteen years time looms large and ominous.

All that is left to say is: enjoy the Day for World Audiovisual Heritage! Treasure whatever endangered media species flash past your eyes and ears. Be sure to consider any practical steps you can take to ensure the films and audio recordings that are important to you remain operable for many years to come.

Posted by debra in audio tape, video tape, 0 comments

Big Data, Long Term Digital Information Management Strategies & the Future of (Cartridge) Tape

What is the most effective way to store and manage digital data in the long term? This is a question we have given considerable attention to on this blog. We have covered issues such as analogue obsolescence, digital sustainability and digital preservation policies. It seems that as a question it remains unanswered and up for serious debate.

We were inspired to write about this issue once again after reading an article that was published in the New Scientist a year ago called ‘Cassette tapes are the future of big data storage.’ The title is a little misleading, because the tape it refers to is not the domestic audio tape that has recently acquired much counter cultural kudos, but rather archival tape cartridges that can store up to 100 TB of data. How much?! I hear you cry! And why tape given the ubiquity of digital technology these days? Aren’t we all supposed to be ‘going tapeless’?

The reason for such an invention, the New Scientist reveals, is the ‘Square Kilometre Array (SKA), the world’s largest radio telescope, whose thousands of antennas will be strewn across the southern hemisphere. Once it’s up and running in 2024, the SKA is expected to pump out 1 petabyte (1 million gigabytes) of compressed data per day.’

SKA_dishes

Image of the SKA dishes

Researchers at Fuji and IBM have already designed a tape that can store up to 35TB, and it is hoped that a 100TB tape will be developed to cope with the astronomical ‘annual archive growth [that] would swamp an experiment that is expected to last decades’. The 100TB cartridges will be made ‘by shrinking the width of the recording tracks and using more accurate systems for positioning the read-write heads used to access them.’

If successful, this would certainly be an advanced achievement in material science and electronics. Smaller tape width means less room for error on the read-write function – this will have to be incredibly precise on a tape that will be storing a pretty extreme amount of information. Presumably smaller tape width will also mean there will be no space for guard bands either. Guard bands are unrecorded areas between the stripes of recorded information that are designed to prevent information interference, or what is known as ‘cross-talk‘.They were used on larger domestic video tapes such as U-Matic and VHS, but were dispensed with on smaller formats such as the Hi-8, which had a higher density of magnetic information in a small space, and used video heads with tilted gaps instead of guard bands.

The existence of SKA still doesn’t explain the pressing question: why develop new archival tape storage solutions and not hard drive storage?

Hard drives were embraced quickly because they take up less physical storage space than tape. Gone are the dusty rooms bursting with reel upon reel of bulky tape; hello stacks of infinite quick-fire data, whirring and purring all day and night. Yet when we consider the amount of energy hard drive storage requires to remain operable, the costs – both economic and ecological – dramatically increase.

The report compiled by the Clipper Group published in 2010 overwhelmingly argues for the benefits of tape over disk for the long term archiving of data. They state that ‘disk is more than fifteen times more expensive than tape, based upon vendor-supplied list pricing, and uses 238 times more energy (costing more than the all costs for tape) for an archiving application of large binary files with a 45% annual growth rate, all over a 12-year period.’

This is probably quite staggering to read, given the amount of investment in establishing institutional architecture for tape-less digital preservation. Such an analysis of energy consumption does assume, however, that hard drives are turned on all the time, when surely many organisations transfer archives to hard drives and only check them once every 6-12 months.

Yet due to the pressures of technological obsolescence and the need to remain vigilant about file operability, coupled with the functional purpose of digital archives to be quickly accessible in comparison with tape that can only be played back linearly, such energy consumption does seem fairly inescapable for large institutions in an increasingly voracious, 24/7 information culture. Of course the issue of obsolescence will undoubtedly affect super-storage-data tape cartridges as well. Technology does not stop innovating – it is not in the interests of the market to do so.

Perhaps more significantly, the archive world has not yet developed standards that address the needs of digital information managers. Henry Newman’s presentation at the Designing Storage Architectures 2013 conference explored the difficulty of digital data management, precisely due to the lack of established standards:

  • ‘There are some proprietary solutions available for archives that address end to end integrity;
  • There are some open standards, but none that address end to end integrity;
  • So, there are no open solutions that meet the needs of [the] archival community.’

He goes on to write that standards are ‘technically challenging’ and require ‘years of domain knowledge and detailed understanding of the technology’ to implement. Worryingly perhaps, he writes that ‘standards groups do not seem to be coordinating well from the lowest layers to the highest layers.’ By this we can conclude that the lack of streamlined conversation around the issue of digital standards means that effectively users and producers are not working in synchrony. This is making the issue of digital information management a challenging one, and will continue to be this way unless needs and interests are seen as mutual.

Other presentations at the recent annual meeting for Designing Storage Architectures for Digital Collections which took place on September 23-24, 2013 at the Library of Congress, Washington, DC, also suggest there are limits to innovation in the realm of hard drive storage.  Gary Decad, IBM, delivered a presentation on the ‘The Impact of Areal Density and Millions of Square Inches of Produced Memory on Petabyte Shipments for TAPE, NAND Flash, and HDD Storage Class‘.

For the lay (wo)man this basically translates as the capacity to develop computer memory stored on hard drives. We are used to living in a consumer society where new improved gadgets appear all the time. Devices are getting smaller and we seem to be able buy more storage space for cheaper prices. For example, it now costs under £100 to buy a 3TB hard drive, and it is becoming increasingly more difficult to purchase hard drives which have less than 500GB storage space. Compared with last year, a 1TB hard drive was the top of the range and would have probably cost you about £100.

A 100TB storage unit in 2010, compared with a smaller hard drive symbolising 2020.

Does my data look big in this?

Yet the presentation from Gary Decad suggests we are reaching a plateau with this kind of storage technology – infinite memory growth and reduced costs will soon no longer be feasible. The presentation states that ‘with decreasing rates of areal density increases for storage components and with component manufactures reluctance to invest in new capacity, historical decreases in the cost of storage ($/GB) will not be sustained.’

Where does that leave us now? The resilience of tape as an archival solution, the energy implications of digital hard drive storage, the lack of established archival standards and a foreseeable end to cheap and easy big digital data storage, are all indications of the complex and confusing terrain of information management in the 21st century. Perhaps the Clipper report offers the most grounded appraisal: ‘the best solution is really a blend of disk and tape, but – for most uses – we believe that the vast majority of archived data should reside on tape.’ Yet it seems until the day standards are established in line with the needs of digital information managers, this area will continue to generate troubling, if intriguing, conundrums.

Posted by debra in audio tape, video tape, 0 comments

Digitisation strategies – back up, bit rot, decay and long term preservation

In a blog post a few weeks ago we reflected on several practical and ethical questions emerging from our digitisation work. To explore these issues further we decided to take an in-depth look at the British Library’s Digital Preservation Strategy 2013-2016 that was launched in March 2013. The British Library is an interesting case study because they were an ‘early adopter’ of digital technology (2002), and are also committed to ensuring their digital archives are accessible in the long term.

Making sure the UK’s digital archives are available for subsequent generations seems like an obvious aim for an institution like the British Library. That’s what they should be doing, right? Yet it is clear from reading the strategy report that digital preservation is an unsettled and complex field, one that is certainly ‘not straightforward. It requires action and intervention throughout the lifecycle, far earlier and more frequently than does our physical collection (3).’

The British Library’s collection is huge and therefore requires coherent systems capable of managing its vast quantities of information.

‘In all, we estimate we already have over 280 terabytes of collection content – or over 11,500,000 million items – stored in our long term digital library system, with more awaiting ingest. The onset of non-print legal deposit legislation will significantly increase our annual digital acquisitions: 4.8 million websites, 120,000 e-journal articles and 12,000 e-books will be collected in the first year alone (FY 13/14). We expect that the total size of our collection will increase massively in future years to around 5 petabytes [that’s 5000 terabytes] by 2020.’

All that data needs to be backed up as well. In some cases valuable digital collections are backed up in different locations/ servers seven times (amounting to 35 petabytes/ 3500 terabytes). So imagine it is 2020, and you walk into a large room crammed full of rack upon rack of hard drives bursting with digital information. The data files – which include everything from a BWAV audio file of a speech by Natalie Bennett, leader of the Green Party after her election victory in 2015, to 3-D data files of cunieform scripts from Mesopotamia, are constantly being monitored by algorithms designed to maintain the integrity of data objects. The algorithms measure bit rot and data decay and produce further volumes of metadata as each wave of file validation is initiated. The back up systems consume large amounts of energy and are costly, but in beholding them you stand in the same room as the memory of the world, automatically checked, corrected and repaired in monthly cycles.

Such a scenario is gestured toward in the British Library’s long term preservation strategy, but it is clear that it remains a work in progress, largely because the field of digital preservation is always changing. While the British Library has well-established procedures in place to manage their physical collections, they have not yet achieved this with their digital ones. Not surprisingly ‘technological obsolescence is often regarded as the greatest technical threat to preserving digital material: as technology changes, it becomes increasingly difficult to reliably access content created on and intended to be accessed on older computing platforms.’ An article from The Economist in 2012 reflected on this problem too: ‘The stakes are high. Mistakes 30 years ago mean that much of the early digital age is already a closed book (or no book at all) to historians.’

Destroyed Hard Drive

There are also shorter term digital preservation challenges, which encompass ‘everything from media integrity and bit rot to digital rights management and metadata.’ Bit rot is one of those terms capable of inducing widespread panic. It refers to how storage media, in particular optical media like CDs and DVDs, decay over time often because they have not been stored correctly. When bit rot occurs, a small electric charge of a ‘bit’ in memory disperses, possibly altering program code or stored data, making the media difficult to read and at worst, unreadable. Higher level software systems used by large institutional archives mitigate the risk of such underlying failures by implementing integrity checking and self-repairing algorithms (as imagined in the 2020 digital archive fantasy above). These technological processes help maintain ‘integrity and fixity checking, content stabilisation, format validation and file characterisation.’

Archival Gold Disc

300 years, are you sure?

Preservation differences between analogue and digital media

The British Library isolate three main areas where digital technologies differ from their analogue counterparts. Firstly there is the issue of ‘proactive lifestyle management‘. This refers to how preservation interventions for digital data need to happen earlier, and be reviewed more frequently, than analogue data. Secondly there is the issue of file ‘integrity and validation.’ This refers to how it is far easier to make changes to a digital file without noticing, while with a physical object it is usually clear if it has decayed or a bit has fallen off. This means there are greater risks to the authenticity and integrity of digital objects, and any changes need to be carefully managed and recorded properly in metadata.

Finally, and perhaps most worrying, is the ‘fragility of storage media‘. Here the British Library explain:

‘The media upon which digital materials are stored is often unstable and its reliability diminishes over time. This can be exacerbated by unsuitable storage conditions and handling. The resulting bit rot can prevent files from rendering correctly if at all; this can happen with no notice and within just a few years, sometimes less, of the media being produced’.

A holistic approach to digital preservation involves taking and assessing significant risks, as well as adapting to vast technological change. ‘The strategies we implement must be regularly re-assessed: technologies and technical infrastructures will continue to evolve, so preservation solutions may themselves become obsolete if not regularly re-validated in each new technological environment.’

Establishing best practice for digital preservation remains a bit of an experiment, and different strategies such as migration, emulation and normalisation are tested to find out what model best helps counter the real threats of inaccessibility and obsolescence we may face in 5-10 years from now. What is encouraging about the British Library’s strategic vision is they are committed to ensuring digital archives are accessible for years to come despite the very clear challenges they face.

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From digital files back to analogue tape

The bread and butter work of Greatbear Analogue and Digital Media is to migrate analogue and digital magnetic tape to digital files, but recently we were asked by a customer to transfer a digital file to ¼ analogue tape.

The customer was concerned about the longevity of electronic digital formats, and wanted to transfer his most valued recordings to a tangible format he knew and trust. Transferring from digital to analogue was certainly more expensive: the blank tape media cost over £50 alone.

In a world where digital technology seems pervasive, remaining so attached to analogue media may appear surprising. Yet the resilience of tape as a recorded medium is far greater than is widely understood.

Take this collection of old tapes that are in the back yard of the Greatbear office. Fear not customers, this is not what happens to your tapes when you send them to us! They are a collection of test tapes that live outside all year round without shelter from the elements. We use them to test ways of treating degraded tapes because we don’t want to take unnecessary risks with our customers’ material.

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Despite being subject to pretty harsh conditions, the majority of material on these tapes is recoverable to some degree.

Would digital data stored on a hard drive survive if it had to endure similar conditions? It is far less likely.

Due to its electronic composition digital data is fragile in comparison with analogue magnetic tape. This is also the ironic conclusion of Side by Side (2012), the documentary film narrated by Keanu Reeves which explores the impact of digital technology on the film industry.

Requests for digital to analogue transfers are fairly rare at Great Bear, but we are happy to do them should the need arise!

And don’t forget to back up your digital files in at least three different locations to ensure it is safe.

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Real time transfers – digitising tape media

In theory the work we do at Greatbear is very simple: we migrate information from analogue or digital magnetic tape to electronic digital files.

Once transferred, digital files can be easily edited, tagged, accessed, shared or added to a database. Due to the ubiquitous nature of digital media today, if you want to use your data, it needs to be in a digital form.

In practice however, there are a lot more issues that arise when migrating tape based media. These can stem from the obsolescence of machines (spare parts being a particular issue), physical problems with the tape and significantly, the actual person-time involved in doing the transfer.

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While large institutions like the Library of Congress in USA can invest in technology that enables mass digitisation like those developed by Samma Systems, most transfers require operators to do the work. The simple truth is that for fragile and obsolete tape media, there is no other option. In the film ‘Living Archive – Preservation Challenge‘ David Crostwait from American digitisation company DC Video describes the importance of careful, real time transfers:

‘When a tape is played back, that tape starts from the very beginning and may run for 60-65 minutes straight. One person sits in front of that machine and watches that tape from beginning to end, s/he does nothing else but watch that tape. We feel this procedure is the only way to guarantee the highest quality possible.’

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At Greatbear we echo this sentiment. We give each transfer individual attention so that the information is migrated accurately and effectively. Sometimes this means doing things slowly to ensure that tape is spooled correctly and the tension within the tape pack is even. If transfers are rushed there is always the danger that tape could get crumpled or damaged, which is why we take our time.

 

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Archiving for the digital long term: information management and migration

As an archival process digitisation offers the promise of a dream: improved accessibility, preservation and storage.

However the digital age is not without its archival headaches. News of the BBC’s plans to abandon their Digital Media Initiative (DMI), which aimed to make the BBC media archive ‘tapeless’, clearly demonstrates this. As reported in The Guardian:

‘DMI has cost £98.4m, and was meant to bring £95.4m of benefits to the organisation by making all the corporation’s raw and edited video footage available to staff for re-editing and output. In 2007, when the project was conceived, making a single TV programme could require 70 individual video-handling processes; DMI was meant to halve that.’

The project’s failure has been explained by its size and ambition. Another telling reason was cited: the software and hardware used to deliver the project was developed for exclusive use by the BBC. In a statement BBC Director Tony Hall referred to the fast development of digital technology, stating that ‘off-the-shelf [editing] tools were now available that could do the same job “that simply didn’t exist five years ago”.’

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The fate of the DMI initiative should act as a sobering lesson for institutions, organisations and individuals who have not thought about digitisation as a long, rather than short term, archival solution.

As technology continues to ‘innovate’ at startling rate,  it is hard to predict how long the current archival standard for audio and audio-visual will last.

Being an early adopter of technology can be an attractive proposition: you are up to date with the latest ideas, flying the flag for the cutting edge. Yet new technology becomes old fast, and this potentially creates problems for accessing and managing information. The fragility of digital data comes to the fore, and the risk of investing all our archival dreams in exclusive technological formats as the BBC did, becomes far greater.

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In order for our data to survive we need to appreciate that we are living in what media theorist Jussi Parikka calls an ‘information management society.’ Digitisation has made it patently clear that information is dynamic rather than stored safely in static objects. Migrating tape based archives to digital files is one stage in a series of transitions material can potentially make in its lifetime.

Given the evolution of media and technology in the 20th and 21st centuries, it feels safe to speculate that new technologies will emerge to supplant uncompressed WAV and AIFF files, just as AAC has now become preferred to MP3 as a compressed audio format because it achieves better sound quality at similar bit rates.

Because of this at Greatbear we always migrate analogue and digital magnetic tape at the recommended archival standard, and provide customers with high quality and access copies. Furthermore, we strongly recommend to customers to back up archive quality files in at least three separate locations because it is highly likely data will need to be migrated again in the future.

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