DVD adequate Backup???

[jmhcs]

I am in a somewhat heated discussion with a friend about data backup. He has about 1.8 GB to backup which should not grow substantially in the next 2-3 years.

I say install a DVD writer on his server. It is relatively inexpensive and the media is affordable.

He wants to stay with mag tape. He has had trouble with tape but has many advisors that are advising him to stay with it. We found out the hard way that a 8GB tape does not work in a 20 GB drive. Fortunately, it was no a catastrophe.

The real answer is accuracy. Is DVD as accurate a backup method as tape?

[dajogejr]

There are plus and minuses for both.
On a server, which...tells me it's for business and not just a home network type, Tape is best. It is more reliable than DVD, and...you should use a normal routine with 5 tapes for a weekly backup rotation, or 10 tapes for a two week rotation.
The business needs to decide how much past data retention they need to hold.

But, Tapes are slow, more expensive, need to be changed by a human hand, etc.

DVDs are cheap, easy to use...and just about any new PC or notebook has at least a DVD Reader, if not DVD burner. You can use the DVD from one source to the other.
Burning and restoring a few GB from a DVD is quicker, too.
However, they can get scratched, cracked, etc....

If this is mission critical stuff, I suggest a proper Tape drive, with tapes that have enough data space to fit all you need....

The importance of this data decides if you need the more reliable, more expensive solution or a quick, easy and cheap one...

[Steve R Jones]

I'd use another hard drive over tape any day.

[dajogejr]

For a server Steve? I'd have to say a HDD has a higher failure rate then tapes...plus, you use a few tapes, and only on hard drive.

Really, a RAID5 or RAID 0+1 array, hot swap...is the way to go...however, that's even more bucks...

[orkboss]

I didn't know they were still using tape to back up data.

[Midknyte]

Tape is still one of the most common server backup methods. Tape is the easiest way to do that for large amounts of data. try spanning 20G of data over dvds versus having one tape.

DVDs costs would still add up over time. almost everyone has a dvd drive, so they could potentially see your data. not too many people have tape drives.

there is no right answer. you need to assess the situation and do what fits.

in either case, you should always have one (or more) backups OFFSITE.

[jmhcs]

I appreciate all comments but need to clarify a bit more. Keep in mind the data being saved is only 1.8GB and probably won't exceed 4GB for the next 3 years.

The question asked does not deal with amount of data but rather will DVD offer accurate backup. The issue with tape is you really don't know what you have until you restore. Hopefully, this test has been done before a real data loss. However, this test is more difficult than just open/verifying a folder/file as on a DVD.

It is amazing how many small business owners store their backup in a desk drawer next to the computer. The don't understand the value of off-site until a catastrophe hits, then say "if only".

Anyway, getting back to the question asked, will DVD provide accurate backup assuming the media is handled and stored correctly? It is my backup of choice for small servers. Just need some reinforcement.

[Midknyte]

you can always run the verify function after you burn the dvd. as far as integrity, it comes down the the media and burner. if you have subpar media and try to burn at high speeds, you'll see a lot more errors.

it's the same deal with dvds as far as restores. you can run all the verification checks, but it may still flake out on you. I'd still run test restores just to be safe, but i'm pretty paranoid. I never heard of anyone getting fired for being too cautious.

dvds will probably last longer than magnetic tapes, just given the nature of the media itself.

[orkboss]

Iwas wondering on the lifespan of dvd vs tape. I thought tape would be more prone to deteriorate due to oxidation.

[dajogejr]

It's a coin toss...DVD's can be scratched much easier, as well... Tapes are available in 4GB and up to over 100GB....that's a huge stretch to put all those DVDs together...

[jmhcs]

I'd like to bring this a little bit farther. Mag tape has now been the media of preference. However, this presents a small delima. Consider we first have, or think we have backed up the corrected data to a Travan tape. All is well at this time, at least we think it is.

However, we really don't know unless you go thru the restore process and then test the data against what you think should be there. Keep in mind, on a DVD you can pretty much tell by opening the folders and intergating the data with appropriate programs. Not so with tape.

We now do a restore (from tape) to the main folders and behold, find out the data is bad because of a bad backup you thought was good. Now, not have you only corrupted your good data but your backup is bad. This is a catastrope.

How do you test (easily) without getting into this situation? Maybe GHOST the original drive first?

[dajogejr]

Chances of a tape being bad are probably about the same as scratching a DVD....
However, if you use more than one tape, say...10 for a two week cycle, (5 working days in a week)...the chances of more than one tape being no good vs. a DVD being bad/damages are significantly less.

I'm not sure of others, but Veritas offers verify with their backups, of course, it doubles the backup time. We run backups Tuesday AM through Friday AM, on Saturday's AM backup (week end) we run verify...

I stand by my suggestion above...figuring out how to span more than 4.7 GB of data over several DVDs is much more difficult than getting a 20, 30 or 80GB tape which will do it all...of course, using the proper rotation of more than one tape...

Ghost is not an option on a mission critical application server or file server. Since, it has to be taken down in order to ghost it....way too time consuming...

Especially since my domain controllers dictate DNS, even more nightmare for remote sites using our servers for DNS....

Sure, DVD is quick and easy...but hardly pratical for business of any size and complication!!

[jmhcs]

dajogejr - I agree with what you have said. However, how does one test the original backup to make sure it has worked from the get-go. As you well know, no backup is good until it has been tested. Is it a matter of restoring to a different folder(s) and redirecting the programs to look at them? How do you do this?

[Sterling_Aug]

I still prefer another seperate drive.

[dajogejr]

I'm not sure I follow....
Normally, when I have to restore, it's because:
a. The user deleted a file from a file server (no recycle bin here, boys and girls) or
b. They entered a bunch of wrong or incorrect data. Instead of undoing or erasing the work they've done, I can restore the file from a previous day or date that won't have the changes.

99 times out of 100 for me, I restore the file over the top or in the exact same place. There have a been a few times where I restored to another folder or other location so the user can use one or the other file. The situation dictates the restore routine.

Does this make more sense, Jmhcs?