Tape archiving best practices

Tape archiving offers the most cost-effective form of long-term data retention, but what should you do about ensuring hardware compatibility, data retrieval and maintenance?

Tape archiving offers a cost-effective and durable means of long-term data retention. In terms of the cost per gigabyte, there's nothing to beat it. But tape archiving isn't just a case of moving data to tape and forgetting it. Tape archiving requires planning to ensure, for example, rapid access in case of an e-discovery request, tape maintenance must be factored in, and there are issues of hardware planning that stretch way into the future.

In this interview, SearchStorage.co.UK Bureau Chief Antony Adshead speaks with Martin Taylor, converged network manager at the Royal Horticultural Society, about the definition of tape archiving and key best practices, such as ongoing hardware compliance, service-level agreements with archiving providers, encryption and ensuring access to data.

You can read the transcript or download the tape archiving podcast.

What is tape archiving, and why is it different to backup?

Taylor: The first thing we've got to do is differentiate between archiving and backup. Backup is a series of files backed up to a tape drive in this instance and also as online copies. With archiving, the online copies aren't retained and the data is stored away for access possibly at a later date for regulatory compliance or other [business-specific reasons].

It's a different mind-set. Backups you can get back easily; archives can be harder to retrieve. When you're archiving, you've got to be able to search your data, you want it to be secure, and you really want it to keep it with a provider that meets your service-level requirements and that you can trust for the long term.

But, the basic definition of tape archiving is that there is no online copy for quick retrieval; everything is vaulted for the long term. There may well be some best practices associated with that that I'll go into in the next question. It's a case of how long … you want to keep it, why … you need it and [whether] you have the facility to get that data back should you require it.

What are the key best practices in tape archiving?

Taylor: If we start at the bottom level, we're talking about hardware compliance. You construct your archive, write it to tape and obviously you'll want to decide whether that data's encrypted or not for security purposes, and then you need to put it somewhere for the long term.

Long-term storage of tape can require special facilities; in extreme circumstances, we're talking about [potential damage from] an electromagnetic pulse or solar flares, and your tapes could be destroyed by environmental factors that your own site doesn't have the ability to deal with. So, the first thing [to] do is to move it off to an archiving service.

Once you've moved it to the archiving service, you should be very tight with your service--level agreements depending on what your needs for data retrieval are. A lot of companies will guarantee retrieval within a certain time period depending on the location of their storage facility to where your [data] is.

Once the data is in the hardware, you need to maintain it so you can access it over time. Obviously, media will expire over time as new standards emerge, so you need to write a plan as well in order to keep the hardware current so you can get the data off it.

The two main factors around archiving are where … you keep your data, the hard media (do you use a service provider or do you construct your own hardware?) and how … you access the data in the long term.

So, archiving also needs to consist of an ongoing process of review, not only of hardware but also of data encryption standards, of service-level agreements for accessing data and how the [tape archive] is going to be maintained. Obviously, archives have a habit of growing over time so you need to standardise your data across the same archive media, and there has to be a cut-off point where you make a decision on changing the media standard, which means pulling off the whole archive, restoring it and then rewriting it.

Once you have your data on tape, there's the question of how you search the data and how you access it. Archiving technology generally involves complex metadata that will allow you to search across your archive and pull out what you need. But, you need a good indexing system with tapes as well; this relies on effective internal admin and having someone who has ownership of that process.

During this podcast, we've looked at the main issues of archiving. I think really the first thing to do is to look at the process around how you deal with your data, what goes into the archive and what the retention [and retrieval] requirements are for the data. So, really, you need to pull together an overview plan that should deal with the long term. It should define the archive, where it's going to live and how you're going to get the data back.

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