How reliable are external HDs?

I used to back up my data every 1 or 2 months, using four or five DVDs each time. It was a sort of cumulative back up, and each new DVD had about 80% of info that was already backed up a month before. I did that so if one of the DVDs failed I wouldn't loose so much.
But with the advent of good and large external HDs, I'm using those now, backing up more often and all in one place.
So I wonder... How reliable are they? I mean, a DVD is pretty reliable, cause most of the time I only use them once (ie. after formatting) and then I just store them. Also, since I used ~5 DVDs per time on a cumulative back up, loosing one of them wasn't too terrible. Now all the eggs are on the same basket (all the info on the same drive). Can I trust it's going to be safe?
What do you guys think?

 

if backup is so important set up an external raid5 array. this way its comfortable and safe (not cheap though). as to single hdd vs. dvds i would go with dvds

 

A single external HDD is just as reliable as a single internal HDD. If you think the internal HDD is reliable, so is the external HDD and vice versa. But having one backup copy is still more reliable than without. If you are afraid, then get 2 external HDD.

 

I've been using external HDDs for a few yrs now and have had no problems.

But I do hear people losing their data if there external HDD is performing an action

I use DVD's for some things. Like you said you usually use them, and then store them so nothing will happy to them. But you could get like a 40GB external HDD, backup your files, and store it just like you do with your DVDs. Then when you're ready to back everything up again either format the HDD or delete everything and reuse

 

I think another option would be a Blu-ray burner. 40gb a disc!!!

 

25gb single layer vs 50gb double layer.

 

Key phrase there. Very true. Actually though, an external hard drive is much more reliable than a DVD. So you're likely in fine shape.

It really depends on how important that backup data is to you. If it's your MP3 collection, then I think the drive is sufficient. However, if it is data that if lost will cost you $5,000,000 worth of business dealings, then you should get a few backup devices. Just to have an extra basket .

 

If you are looking for security and something with minimum risk of losing valuable data, then you should invest in an Iomega Rev. Very good, good capacity (up to 120GB per disk), but expensive hardware and not cheap disks. (not discs ;p ).

External hard drives are as trustworthy as internal, which means IMO, it's a hit or miss thing. The potential problem with the external HDDs are the actual enclosures which are not always the best in quality and might be the reason for data failure.
From personal experience and having used WD, Lacie and Iomega external hard drives, my favourite is the Iomega. The Lacie died on me after 2 years, the WD after 1 day and the Iomega is still working after 7 years, though not so much in 2008.
Having said that, I haven't bought an Iomega hard drive since then, so I don't know what is the reliability of them now, but I trust them for one reason or the other.

If I were you and wasn't considering buying an Iomega Rev, then I would get the external HDD(s) but also every X amount of time (6 months, 1 year?) I would also copy everything to DVDs.