AWS Glacier's dazzling price benefits melt next to the cost of tape

AWS Glacier's dazzling price benefits melt next to the cost of tape

Summary: Amazon's tape-replacing cloud storage service costs far more than the types of on-premise kit it is attempting to supersede.

TOPICS: Cloud, Amazon, Storage

Amazon launched its Glacier storage service on Tuesday, aiming to entice enterprises to put their data in its cloud. But how does the cost of the new cloud archival service stack up against a typical on-premise tape installation?

Werner Vogels, Amazon's chief technology officer, said in a blog post this week that Glacier's price of $0.01 per gigabyte per month made it "extremely cost-effective", and also explicitly described Glacier as an alternative to "cold data storage systems such as tape robots and tape libraries".

AWS Glacier
Will AWS Glacier cost you less than traditional tape storage? Image credit: AWS

But is it that much of an alternative? To find out, I asked tape specialist Quantum to give me a breakdown of the cost of storing 10PB in tape systems over five years.

The total cost of storing 10PB over five years with the company would work out at $669,663.70 (€533,341.61) in total — or $133,932.70 (€106,772.53) per year, Quantum told me.

The majority of this expenditure comes from buying a high-end i6k tape storage array ($450,610.12 or €358,966.08), and the next highest expenditure ($135,198.32 or €107,702.00) is buying the LTO-5 tapes to store data on it. The third is the $75,433.84 (€60,092.28) cost of a support package that provides next business day onsite support in case of failures. There's also a small cost ($8,261.44 or €6,581.25) for installing the equipment onsite.

So how does this compare with Glacier? Admirably. To store the same amount of storage in Glacier for five years costs $6.3m when storing it in the cheapest datacentre region of North Virginia.

I got to this figure by converting 10 petabytes into gigabytes — 10,485,760 gigabytes — and multiplying the figure by the cost of storing a gigabyte ($0.01) to get a cost of $104,857.60 a month. I then multiplied this by 60.

$6m versus $600,000

So, a simple comparison shows us that Glacier is almost 10 times as expensive as an on-premise tape system with support.

However, it's important to note that Amazon has a few advantages, specifically around the rate at which Glacier can ingest data and the fact that all administration is outsourced to Amazon. Those differences would be worth going into further details about if the price difference was smaller, but at a 10x difference, it seems tape is still king for very large storage deployments. The cloud has a way to go yet.

Additionally, businesses pay no upfront costs for Glacier and its fees are levied monthly, compared to a hefty upfront capital expenditure for those going down the on-premise route. This is likely to be an issue for small firms, but such companies are unlikely to want to archive a whopping 10 petabytes (unless they're Instagram, at least).

Readers, what do you think? Does Amazon have a chance of replacing tape, or is the price difference, combined with cloud-fear, just too much?

Update: Friday 8pm BST

In light of this piece, Amazon crunched the costs of Glacier compared to an on-premises tape solution. Their analysis finds that tape works out to be significantly more expensive than Glacier over the five year period, when you take into account overall storage utilisation, electricity costs, bandwidth and other factors. 

I understand they will be publishing this information in a blog post this weekend, and once they do I'll come back here with an analysis of the implications of their findings. 

Topics: Cloud, Amazon, Storage

Jack Clark

About Jack Clark

Currently a reporter for ZDNet UK, I previously worked as a technology researcher and reporter for a London-based news agency.

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.


Log in or register to join the discussion
  • Restore?

    How long would it take to restore 10 PB, tape vs. cloud?

    Restoring only subsets of data may be where the cloud has a major advantage.
  • Two things

    First, there is no offsite storage in that calculation. Second, there is no bandwidth cost.
    • more things

      How about labor costs? What about disaster recovery? What about all of us who are still measuring our storage in TB and not PB? There are many pros and cons that will lead to selecting either a cloud based or premise based solution including many non dollar cost factors. Once you reach the decision to use cloud storage, that .01 per GB is about as cheap as it gets.
      • Bandwidth not calculated due to Amazon policies

        Hey happyharry_z,
        I didn't calculate the bandwidth costs as Amazon has an option that lets you directly mail them your stored data which they upload for you from within their network. This would probably be how you'd transfer data into Glacier if it was in the petabytes as bandwidth costs would (you're right) be very painful otherwise.
        Jack Clark
  • Who would put their customer data in the cloud in the first place? (N/T)

  • 10PB? Really?

    Man I read this article expecting something useful. I got 10PB of blah.

    I will have to do the math myself for 800GB or even 4 TB, but I bet it is plenty cheap. Much cheaper than tape. BUT, do they have good backup solution software? From what I see on their site they do not.

    It is more of a store your data not back it up. I pay over $1000 a month to back up my data (Offiste). Come on Amazon, get some backup programs. Then I will be only paying 40.96.!!
    • Glacier great for small quantities

      Hey @bin00010111
      You're right, Glacier does seem to work out much cheaper for small amounts of data - the purpose for this article was to explore how it behaves under very large loads.
      Jack Clark
    • Glacier Software

      We are working to add Glacier support to MagnaStor (, our archival filesystem. It currently supports S3. Please have a look and let me know if this is the kind of software you're looking for?
  • Major Tape Advantage

    An unmentioned advantage to having your own tape store is the ability to "lose", and I mean really, effectively, totally lose, your old data. For instance, if you have a company policy of destroying all emails after say 2 years, you can actually do that with a tape store. Just burn the tape. It's gone, and if you scrub your company machines regularly, it is practically impossible to retrieve old emails.

    Depending on your company business model, this feature can offer real, practical utility. And strategic advantage. Just ask Samsung.
  • What is this?

    This is an absolutely terrible story, what on earth does it say about zdnet?
    Offsite storage of tape? Electricity and the biggest killer
    "support package that provides next business day onsite support in case of failures."
    So these guys are willing to go a day without backing anything up?

    Just shocking shoddy stories

    Cloud computing costs lazy admins there jobs
  • good story...tape can still make sense

    Hi, interesting article,
    I'm not sure that Cloud based backup is really competing right now with in-house tape libraries, as the positioning is slightly different.
    I've worked many years as product manager in the cloud/hosting industry, and I can confirm your point of view, for big volumes (whatever your talking about CPU Ghz or GB of storage or whatever) it's always more interesting to buy the solution than rent it as a service.
    Tape still makes a lot of sense from a cost advantage, and the density is increasing with the LTO6. Cloud offers flexibility, ease of use. Both solutions are great, I just think they adress different types of customers and needs.
    I'm happy to see that people can still keep some pragmatism, not everything needs to be "cloud"...
    There are pros an cons on each side...and I don't know about you, but even with SLAs, bandwidth not always work :) and I don't care about getting 10$ of penalties because of an outage, I need the service to work. SLA is like an insurance, not a guarantee... it's so easy to say uptime for 99.999% of the time....if the penalties at the end are low.
    So for my critical data, and if I have a high volume...I may choose tape...
    For less critical data, and lower volume I might choose Cloud based storage.
    Or...mix the two :)
    Last point, true that there are many other hidden costs, but again, having done some business plans around this kind of offers, brainer, you can cover a lot of headcounts, offices, power, cooling for the 5.7M$ of difference :)
    my 2 cents
  • comparing apples with oranges...

    Overall an interesting article - but too many mistakes on the comparison of cost:

    AWS Glacier = total cost of ownership of long term archiving x GB of data with an SLA of 99.xxxxxxxx%

    Quantum solution = Mainly CAPEX (and some direct related OPEX like support contract) BUT no OPEX for power / cooling / data center rent / network equipment / network bandwidth / staff costs / legal&auditing costs / opportunity costs for over-/under-sizing the solution etc.

    I think it would be interesting to calculate the case to compare break-even of the two solutions, but please compare apples with apples....