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Tape Drive and archiving advice

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October 9, 2009 7:24:47 AM

Im looking for advice on the best way to archive work projects etc.
Im looking to buy a tape drive to archive but have had mixed reactions as to their reliabilty and usabilty.
I work with video files so archiving to DVD has become too time consuming and complicated because they dont hold enough data.
I have been advised to just archive to pocket hard drives but that would work out too costly in the long term as I would want to have 2 copies of everything in case of failure (I know tapes can fail too!)

Also I am confused about the serial nature of the way data is stored on a tape drive as I understand it is a painful process to access compared to a hard drive...could someone explain a little more about how the info is accessed?

If anyone has any other ideas for archiving that works for them then any advice would be helpful

Thanks!
a c 342 G Storage
October 9, 2009 2:10:10 PM

Tape storage is, of necessity, a sequential medium. You cannot get to an arbitrary spot on the tape to access its data without winding through all the tape previous to it.

If your backup dataset was originally a copy of everything you are backing up - say, an entire hard drive - and you want to restore just the files in one folder, the restore software has to read through most of the file listings on the tape record until it comes to the specific folder you are looking for, then restore from there. If, instead, you backed up all the major folder as separate datasets but on the same tape, one after another, the restore software still has to skim through the tape looking for the dataset that contains the folders you want.

A hard drive, of course, does not have these time delays in finding data because it is not a sequential device. However, until a decade or so ago, HDD's were a lot more expensive than tape per gigabyte of storage. That probably is no longer true.

To compare pricing, put together the two complete systems "on paper". For tape you will need a drive (and mounting case or internal, and connection cabling) and a significant number of tapes. To do your first complete backup you can calculate the number of tapes needed to back up say, 400 GB, if that's the space currently occupied on your HDD. After that if you practice incremental backups you can calculate how many additional tapes you need for them, up to the point where you start the cycle over again. Now, if you want to have TWO backup copies (one at least stored off-site), double that. Add a few spares in case you run into a bad tape. Put that all together and that's your initial investment in the system.

An important factor today is who will change the tapes, and how? HDD's are so big it is normal that a tape backup system will require use of several tapes for one HDD. So either you have to be there, waiting to change tapes in the drive, or you need to buy a tape drive with an automatic changer and capacity of (you figure out how many) tapes.

For hard drives instead, choose one or more external hard drives a little larger than your machine's HDD. If your main machine has more than one HDD, consider whether your backup unit should be sized to allow making backups of ALL your machine's drive to one external. Also consider again whether you will do a scheme of full backup plus several incrementals, and how many external drives you need for that. Now, if you're still going with duplicate backups and off-site storage, double your external hardware design.

By the way, many people find they can save money and get exactly the hardware they want by buying an external case, hard drives, and backup software separately and building their own system. If you do that, consider also cases that allow mounting two or more drives in the same case. Pay attention, too, to the type of interface between the external enclosure and the computer, because they differ a lot in speed and that will be important for long jobs copying a LOT of data. Others are much more comfortable with a complete package from one source. But I suspect among these, "pocket drives" built for use with laptops may be the most expensive option.

Another option to consider, whether for all of the system or just for the second off-site copy, is backing up via the internet to a remote backup service.

Once you put on paper all the components of each system - tape versus external hard drives, maybe also internet services - you can compare costs. My guess is the external HDD option won't be much more expensive. The difference may be worth it for the speed and convenience of making backups and restoring via HDD compared to tape.
October 9, 2009 2:31:15 PM

Thanks so much for all that info paperdoc.

Loads to think about there. It does seem to be six of one and half a dozen of the other.

I guess the main use for what ever I end up going with will be just archiving old jobs. I dont see myself regularly accessing the data so maybe the tape drive is the best option....

I did also consider buying cheaper Hard drives specifically for the purpose of archiving then just put them in a $10 enclose to protect them once they are full.
This would be cheaper than buying a complete enclosed 'readymade' Hard Drive

Ive had a run of drives failing on me and Ive got it in my head that its not the most reliable way to keep stuff!


Incidentally are there any rumblings of any of the tape formats being phased out at all?
Last thing I want to do is start archiving only to find that Im stuck, if, in the future, the tape drive fails!

Thanks again for the advice
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a b G Storage
October 9, 2009 2:33:32 PM

I would go either with an external hard drive or a NAS.
If you have an old computer, you can use FreeNAS or Openfiler.
Ubuntu or Solaris with ZFS is another option.
October 9, 2009 2:54:34 PM

Thanks Evongugg

Ive not used NAS before, although I know its a network set up.......how would I make best use of it for archiving?
a c 415 G Storage
October 10, 2009 7:52:15 AM

mattw said:
Ive had a run of drives failing on me and Ive got it in my head that its not the most reliable way to keep stuff!
ANY media can fail, be it hard drive, tape, DVD, or anything else. What you need for backup is to keep multiple cycles of backup media so that if one fails you still have another one to fall back to. In an extreme case, you can use backup software which writes two identical copies to two different media. Again, this would apply not only for disks, but for tapes or other backup media as well.

IMHO tape is on the way out. Tape drives and media are having a difficult time keeping up with the increasing capacity and falling cost of hard drives. Tape has the advantage of speed if you've got the right hardware, but the right backup package can write to multiple hard drives drives in parallel if that's an issue (although that will probably increase the media cost).

I don't "get" the idea of backing up to a NAS. Good backup policy dictates that at a minimum you have two or more offline copies of data and you store at least one of them offsite. I don't see how a NAS meets the offsite requirement, unless it's located in a remote location - and even then it doesn't meet the offline requirement unless it's powered off most of the time. Maybe the idea is to use it as a receptacle for disks which you swap in and out of it?
a c 114 G Storage
October 10, 2009 7:10:38 PM

I use an NAS (Infrant NV+, now marketed by Netgear). However, a fire is going to take out both so I also back up everything to my laptop HD as well as DVD's. If I had larger amounts of storage, I'd consider a BlacX and spare HD's stored off site.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...
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