Lasting data integrity

vbimport

#1

I’ve been buying blank DVD discs for some time (Taiyo Yuden/Verbatim). However, instead of buying more blank discs, I’ve been thinking of buying a second internal harddrive for my tower. Currently I only have one in my tower.
Economically, blank discs are the way to go per GB.

The only drawback is I have to fetch “that particular disc” whereever it is. With a harddrive, it’s much easier to fetch a certain file.

My question to y’all is which is better for lasting data integrity? DVD blanks or a harddrive?

Thank you


#2

I do both, never can be to safe with back-ups.


#3

how long is [B]lasting[/B]? how much data are you backing up? and how often are you needing [B]fetch[/B]?

for me i would go with two external drives.

backup the data and keep it in a fire safe. back up each day to the external and keep it unplugged when not in use. then after one week take out the fire safe drive and do another back up.

but i dont backup anything. this is how ive setup for my fathers business.


#4

Thanx for the replies guys. Hmm, lasting would be as long as possible. I heard 10-20 years is possible. I could have possibly up to 10 GB per day to store, but I am not needing to fetch the files anytime soon. I just would like more bang for my buck when I’m looking for lasting data integrity. I already have an external 160 GB, & another external enclosure with a 60 GB inside of it. My current internal harddrive is a 500 GB. I was gonna go with either another internal 500GB or more blank discs. I only wanna spend $100 for now.

Thanx again for your advice.


#5

internal is not good for backups. :bigsmile: if your computer blows up :eek: then your backup will too. :doh:


#6

The final question is which is better for data integrity, over the years? I hope the quality of the data is still viewable many years down the road.

Thank you all.


#7

A lot depends on how important and or irreplaceable the data is, and how much you want to spend protecting it. Backing up on disk and hard drive is about the safest you can get.

Are you sure you are going to be doing 10 GB per day? a 500 gig drive is going to fill up in about a month and a half? If you really are doing that much, its an expensive approach, but you might want to consider a multi drive raid array (not just a simple 2 drive array). In general if a drive ever fails, you can just swap it for a new one without ever loosing any data (you can do the same with a 2 drive array but it wastes more space than some setups).

If it might actually be less, and external drive and dvd backup might be good idea for important data. A few things to consider with hard drives though. They are not all created equal. Look here for info on hard drive reliability.
http://www.storagereview.com/
They have a huge data base of user reported hard drive life (I think you may have to enter info on one of your hard drives to access it).
Heat kills hard drives, big time. Regardless if you get an external or get an internal and an enclosure, make sure it had good cooling or mod it to have good cooling.
shock kills hard drives (sometimes instantly, and they can take a lot less shock when they are running). Put the hard drive somewhere safe where there is not chance of it getting bumped or knocked over (and or contained in furniture that is not likely to get bumped a lot). Wrap the cord (usb or fire wire) around something so if it gets snagged by someone walking by, it cannot pull the drive down. I have killed an external hard drive just by tipping it over (horizontal mount might be safer than vertical mount even if it takes more room). it did run long enough for me to get most but not all of the data off. I have also snagged a usb cord with my foot dragging and external to the floor, instantly and fatally killing it.
Hare drives can run a certain number of hours and then will die, even if not mistreated. If you go external, don’t leave it running all day if you are not going to be using it all day.

Just a few hints. It really depends on how important and more so how replaceable the data is, how much trouble and or expense you want to go to…


#8

Depending on my broadband speed, it’s possible I’d be doing up to 10 GB daily. Yes it can get expensive… so much so that I’ll most likely continue going with blank DVD discs (4.7gb too, cos dual layer 8.5gb are still not worth buying economically. Blu-Ray prices are too new to drop). I just like the ease of access with internal/external harddrives though sigh.

Hmm, I heard of RAID, but I don’t know much about them. I’ll look into that. All I know is they’re expensive.

Thanx for the website, and for the heat/run-time info. I appreciate it :slight_smile:


#10

Not all raid is that expensive (though some is very expensive). The basic concept is pretty easy to understand. Raid 1 and raid 0 are the most common on home computers, and in fact, most mother boards support them with no additional hardware (except the hard drives of course). raid controller cards are cheap too (starting at about 13$ though more for a good one). for external, there are external 2 drive raid enclosures starting at 43$ on newegg (probably a piece of crap though), but several under 100$. It is generally best to have identical hard drives (not only same size but same exact model, and if possible, same revision etc).

common types of raid

raid 0
This is not for backup, its for speed. I only mention it so you are not wondering what it is. It basically splits your data up into little chunks (often 4-64k) and sends them alternately to both drives. as you are reading and or writing to both drives at the same time, you can move a lot more data in the same time frame.

raid 1
basic mirroring. duplicates of your data are sent to both drives at the same time. you basically have identical copy’s of your data on both drives. The big disadvantage of course, you loose half your space. you are writing the same thing to both drives. You can even use a raid 1 drive as a boot drive (and if 1 drive fails, your system doesn’t even stop working, it keeps running on the good drive till you replace the bad drive, and rebuild the raid array). It only protects against a single drive failure though. If a virus or other software related issues corrupt your data, both drives will probably get corrupted. IF both drives die (lightning strike, power surge, cheap power supply falure), you of course loose your data.

Raid 5.
I haven’t ever used raid 5 but basically, it uses parity data on all the drives, so that if any one drive fails, you can recreate the lost data from the other drives. It requires 3 drives minimum, and on a 3 drive raid, if I am not mistaken, wastes 1 drives worth of space on parity data (so you loose 1/3 your space). IF you loose 2 drives you loose all the data. Raid 5 can work with more than 3 drives but I’m not sure on the particulars. The same concepts of how it works to use parity data to recreate lost data on a lost drive still apply though.
Raid cards for internal raid 5 are not very expensive (better ones of course cost more). External raid 5 is where things seem to get VERY expensive. This one is only about 500$ (with 4 500 gig drives), but it doesn’t seem to be true external raid.
http://www.newegg.com/Product/Product.aspx?Item=N82E16822101049
The true external ones are much more. Fyi, I have seen a few that are saying 1.5GB usable on a 2GB 4 drive raid 5.

Raid 6, similar to raid 5 but allows 2 drives to fail at the same time. If I’m not mistaken it takes even more drives and is even more expensive.

Hope that info helps some. Fyi if you want to go cheap, high capacity, reliable backup (but slow), maybe you should look into tape? Back in the day it use to be good cheap backup and pretty safe as long as you don’t get a magnet near it. I’m not sure about cost of it these days though (its still out there but not quite as main stream as it used to be).