Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm considering moving from DVD-Rs to Blu-Ray Recordable disks to backup my data. I don't have any experience with BD-Rs as of yet, though, and I wonder if it's worth it or I should wait another year or two.

I clearly remember that when DVDs were still the new thing you could reasonably expect a 20% coaster rate, and after one, maybe two years a lot of successfully recorded disks became totally or partially unreadable. Same thing happened years before with CD-Rs.

Considering that as of January 2012 the price of a single BD-R hovers around $2.40, and considering that I need at least 200 of them to move my data, I'm now treading lightly.

I'd appreciate to hear from someone who made the switch and can speak from experience.

As an aside, the cost per gigabyte of BD-Rs seems to be only slightly higher than DVD-Rs': $0.096 for BD-Rs (25 / $2.40) and ~$0.070 for DVD-Rs (4.3 / $0.3). The higher density of BD-Rs, in my opinion, compensates for the slightly higher price. Still, reliability comes first.

share|improve this question
Update about hard disks: Answers so far have been of the "the heck with BD-R, use hard disks" kind or "permanent backup is a myth". So let me clarify my position on both. First off, I know, "permanent" is really not permanent. When I say that, I mean 5-10 years. Technology marches on. Now, hard disks: I approach them with paranoia, because they fail often and unpredictably. For instance: last year I bought two 1.5TB Seagates. Filled them with the most accessed data, kept one online, the other stashed away. The one kept online failed within three months. – Yudo Jan 15 '12 at 19:34
If used properly, hard drives can be very reliable. The key to success is using them in a redundant array, where depending on the setup, one or two discs can fail without any data loss. One good way to achieve this is to create a RAIDZ or a RAIDZ2 array with ZFS. You can set up your workstation to periodically check the integrity of the stored data, so if a drive was failing you would have time to react and replace it, without losing data. – phil Jan 15 '12 at 20:05
I've eaten three hard drives in the last two years, and my data is still safer in my opinion than if I were to write them every three to five years to DVD or BD. I have around 4TB of data, mirrored across at least two drives at a time. It's a manual RAID1, for lack of a better definition, not perfect by any means, but it's still more reliable than the BD scenario. I tried reading a CD-R I burnt in 2006 and it saw the files, but I couldn't read them. – user3463 Jan 16 '12 at 4:34
@RandolphWest: I've gone through at least 6, if we take into account the refurbished manure that Seagate kept sending as a replacement, which itself had to be replaced within two months. Eventually the combined shipping cost was approaching the cost of a new drive (seriously), so I stopped sending them back. That's why I feel kinda paranoid. However yes, all things considered the BD scenario seems to have more cons than pros. I think I'll ultimately stick to what I am doing right now (manual RAID1 is a great definition, actually!) and get some more drives as soon as prices drop. – Yudo Jan 16 '12 at 8:22
If I can suggest anything, it is to avoid Seagate. That said, Western Digital Blue snf Green drives haven't been behaving at all well lately, leaving the Black ones which are pricier. – user3463 Jan 17 '12 at 1:11
up vote 4 down vote accepted

I seriously would recommend you get HDDs as a backup:


  • They are cheaper
  • You can keep your data always up to date
  • You can plug them in anywere
  • Faster Backup

If you check HDD prices today, they are probably quite high, this is still due to the flooding in Thailand, which made the prices for HDDs explode - doubled prices!

share|improve this answer
All things considered, I agree, thanks. I would accept your answer (and upvote the others) but unfortunately I don't have enough reputation to do so. – Yudo Jan 25 '12 at 0:35
Is this still true (Sep 2015)? Also, what about power costs? – einpoklum Aug 21 '15 at 21:22

There is no perfect way to keep data, all media will degrade over time. The best way is multiple backups, probably on different media, kept on different sites to guard against fire, flood, etc.

share|improve this answer
Already doing that. The data I have on DVDs I also keep, partially, on hard disks. Switching to BD-R would also give me the opportunity to countermand the degradation - which is certainly affecting my DVD-Rs as we speak - by moving the data to "fresh" media. Just like I did 10 years ago with my CD-Rs. – Yudo Jan 15 '12 at 19:44

200 BD-R discs * 2.40 = 480$

4 * Seagate Barracuda Green ST2000DL003 2TB 5900 RPM * 150.00 = 600$

If you set up a ZFS RAID-Z array, you would have 6TB of available space and one drive could fail completely, before you would be in trouble.

share|improve this answer
you can't count the barracudas with a price of 150(assuming $) each, that's only a temporary high. – inf Jan 15 '12 at 19:17
I know that very well, however if he needs them right now, that's what he will have to pay for them. – phil Jan 15 '12 at 19:36
$580, actually, since I'd have to buy a BD-R recorder as well. Good suggestion, but we all know that drive will fail. On my personal reliability scale, HDD rate pretty low. I'd rather buy two 3 TB drives at $250 each (current price) and use the same technique I talked about in the comment above. – Yudo Jan 15 '12 at 19:40
ZFS should work in machine with ECC RAM. And it is not a chip one PC – pugnator Mar 4 '15 at 17:50
Umm, what about power costs? Also, what's the 2.40 figure mean for the discs? Their capacity is not 2.40 anything... – einpoklum Aug 21 '15 at 21:23

I was also wondering if BD writers are reliable now. I agree with Xavierjazz - back up to different types of media, and keep them in different locations. I suppose using the "cloud" would be convenient - it is in a different location, but you don't need to leave your home to access it. I definitely wouldn't use the cloud as my only means of backing up though.

Now back to the BD question. I know that in the CD/DVD world, Verbatim and Taiyo Yuden are the top brands of media, so perhaps that is still true when it comes to BD media. Also, after you have burned a CD or DVD, you can use a free program called Nero CD-DVD Speed to test the media and it will give you an idea of what the burn quality is. For example, it reads the media and tells you how many errors the drive encountered (yes, even with perfectly readable media, all drives will encounter thousands of errors - that is normal and part of the specification for optical media). For BD media, there's a new version of the program called Opti Drive Control, which is payware and which I haven't used.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .