Archiving small to moderate dataset -- tape or harddrive?

Question

obviously there are many questions regarding data archiving, but I would like to ask your opinion on given scenario regarding selecting proper method:

• Company has an "archive" of mission critical data around the size of 1.5 TB and growing (the rate is increasing as data get bigger) stored on an RAID6 array (which blew in their face once already due to faulty controller, RAID isn't the answer to everything, right..)
• They need to backup that archive, preferably offsite, as they really cannot afford to loose it
• Cloud etc. is out of the question, due to narrow bandwidth (about 512Kpbs uplink)
• Linux based servers only

So my question is this: would you select tape or hard drive based archiving solution? Disks are cheaper, but their handling seems to be more of an hassle and I'm used to thinking that once you store a tape, you can be pretty sure that you're getting your data back. At least more so than from harddrive, even though it's disconnected and stored somewhere in a locker.

The retention rate for a dataset is not that high, a year back would suffice, provided we create one snapshot once a month (not sure whether to archive it all over again every single time, or use incrementals).

edit:

to clarify the kind of data i am talking about:

• they (the company) are a publishing house with their own DTP department
• there are no legislation related issues regarding long term data storage, no standards to comply to and so forth
• they store large images, and prepared PDF and InDesign (or whatever) files ready for production print
• time to recovery is not an critical issue. Should the total disaster happen, it wouldn't be a problem to wait for recovery hours/days, as the storage in question is not usually used as a working environment for daily use
• they tried blu-ray, but sinnce the data passed certain amount, it just wasn't feasible any-more (two backup sets of the whole archive would be worth about $1000 in media costs alone)
• annual data growth is somewhere between 0.5 to 1TB of data, depending on the work they do, obviously

Answer 1

I think the answer to this depends on the type of data the company are archiving and if there are legal issues around what they have to keep and where. e.g. If there is legislation saying they must keep x years of data in a secure format, etc, etc.

To be honest, if it was under 4TB or so and it wasn't PCI DSS data or anything, I would consider using a couple of small NAS boxes, bringing them in to the building the day a backup was required and then and storing them offsite in two separate places.

e.g. I just built a 12TB RAID box for under $1500.

Or even: You can buy 3TB Western Digital Reds for around $180. You could stick those in a USB enclosure and do it that way! Buy 12 such disks (one a month). Just a (possibly mad) thought.

EDIT: It also depends how and when you want your data back. If you need to recover a single file for somebody from a tape that's a lot more painful than plugging in a USB drive...