The Need for Tape

  • Tapes are simple and compact. I haven't looked recently, but 40Gb tapes were available 5 years ago.

    DVDs can't match the storage (haven't checked Blu-Ray, but the technologies a bit new for general use).

    Removable hard disks can match or execeed the storage but come with a mass of sensitive electronics built into the media which could fail.

    Hence tape is still the backup medium of choice in most situations.

    Derek

  • Derek Dongray (3/26/2009)


    Tapes are simple and compact. I haven't looked recently, but 40Gb tapes were available 5 years ago.

    DVDs can't match the storage (haven't checked Blu-Ray, but the technologies a bit new for general use).

    Removable hard disks can match or execeed the storage but come with a mass of sensitive electronics built into the media which could fail.

    Hence tape is still the backup medium of choice in most situations.

    300 GB HD were available 5 years ago (and bigger). Tape not sensitive?! Very funny. And do you enjoy the time spent backing up to or restoring from tape?

    The speed and capacity of hard disk far outweighs any argument tape can propose. Lets see someone pull off a backup to a mirrored set of tapes... yes, it can be done, but whoa... Electromagnetic interferrence will smoke a tape much easier than a disk.

    Championing tape in this day is like saying we should go back to 486 DX4 100MHZ PCs.

  • After a read, a re-read, and digesting the posts before mine, I've come to the conclusion that the best concept in the discussion is using a pull based method to get the backups from the main server(s) to the backup servers. (Whether the backups are stored on tape or disk). It means the server being backed up doesn't even have a clue (much less any access rights) to where it's backups might be being copied.

    I am one who has abandoned tape a long time ago. But we've been pushing backups to another server, I'm going to reverse that.

    Thanks for the article, and for provoking some thought!


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  • I knew a DBA who:

    (1) Backed up using a script

    (2) zipped up the backup via command line

    (3) Used a QIC 40 tape to backup the zip.

    ATBCharles Kincaid

  • Backup to USB HDDs is pretty good physical alternative to tape. They do take up a bit more shelf space, and cost more.

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  • I still think tape is cheaper for any type of off-site, archival mechanism. Perhaps HDDs can fit, but most places I know can't get all their backups off to disk, in a reasonable time, at a reasonable density, for a length of time. In a few larger organizations, we've run 2 copies of tape to keep one around locally, one off site for the fire/other disaster.

    Maybe the last few years, with the cost/GB of disk crashing, that changes, but I'm not sure. I would really love to see more research here.

    Tapes are offline, physically moved. Disk isn't necessarily.

  • For a good DR strategy, it has to be either tape or some other media that can be taken offline and shipped to offsite storage. Tape is generally easier to deal with for offsite storage and more durable for transport - but any removable media will do.

    When the prices come down, and the capacity goes up a bit - I can see SSD drives as ideal offsite media.

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  • Steve Jones - Editor (3/26/2009)


    I still think tape is cheaper for any type of off-site, archival mechanism.

    (snipped some)

    Maybe the last few years, with the cost/GB of disk crashing, that changes, but I'm not sure. I would really love to see more research here.

    Tapes are offline, physically moved. Disk isn't necessarily.

    Check the cost per GB, not the cost per unit.

    The second part is by choice, not by limitation. They can be used practically identically... just disk is much, much faster.

  • Disconnected media would have prevented a bunch of the damage that Steve mentioned. How one goes about that can be debated - endlessly.

    Magnetic media, all of it, fades over time. On tape you have the problem of "bleed through" distortion. (Ever watch an old movie on the tube and notice that you can hear the woman scream three seconds before she does? That's because the intense field of the scream in the audio on the tape bleeds onto other layers of tape on the reel.) That is avoided with disk but it fades over time as well. Then disks that are tied to a motor have the problem of frozen bearings if the drive is not started for many years.

    There will be challenges with any media that you pick. You have to know the weak points of each. Anyone that says that the backup media, method, whatever, is perfect is trying to hand you a "stimulus package".

    Here is a proposal. Take 16mm film. Use a LASER on a helical scan to record the data (like the old VTRs did). It is write ONCE. No erase or modification. Modern film stock can sit in reasonable room conditions for over 50 years. You don't change backups once made. Same fire concerns as most other tape like media. Yes, you have to send it out for developing. If this catches on then low cost, on-site processors will become available. (Keep this idea just between us. I'm already consulting my friend. Her name is Pat. Pend.)

    ATBCharles Kincaid

  • Charles Kincaid (3/26/2009)


    Here is a proposal. Take 16mm film. Use a LASER on a helical scan to record the data (like the old VTRs did). It is write ONCE. No erase or modification. Modern film stock can sit in reasonable room conditions for over 50 years. You don't change backups once made. Same fire concerns as most other tape like media. Yes, you have to send it out for developing. If this catches on then low cost, on-site processors will become available. (Keep this idea just between us. I'm already consulting my friend. Her name is Pat. Pend.)

    Nice! What kind of speed would you (theoretically) expect from this device? I know the laser can keep up...

    I am still looking forward to the improvements in the SD technology... they claim to have reached a TB on a single card, and that the read/write speeds are approaching disk speeds. No moving parts. I don't know that I'd trust the durability of the data on these (yet)... but sounds interesting.

  • On the tape size vs. disk physical unit size alluded to in a previous post: that used to be true... not any longer; not for the last 3 years. With both SAS and laptop disk size changes, the difference is minmal... and with 2.5" SAS you can get 10,000 RPM.

    I know many places still use tape. I think that is a matter of:

    1. Familiarity.

    2. Perceived cost to switch implementation.

  • Charles Kincaid (3/26/2009)


    Disconnected media would have prevented a bunch of the damage that Steve mentioned. How one goes about that can be debated - endlessly.

    Magnetic media, all of it, fades over time. On tape you have the problem of "bleed through" distortion. (Ever watch an old movie on the tube and notice that you can hear the woman scream three seconds before she does? That's because the intense field of the scream in the audio on the tape bleeds onto other layers of tape on the reel.) That is avoided with disk but it fades over time as well. Then disks that are tied to a motor have the problem of frozen bearings if the drive is not started for many years.

    There will be challenges with any media that you pick. You have to know the weak points of each. Anyone that says that the backup media, method, whatever, is perfect is trying to hand you a "stimulus package".

    Here is a proposal. Take 16mm film. Use a LASER on a helical scan to record the data (like the old VTRs did). It is write ONCE. No erase or modification. Modern film stock can sit in reasonable room conditions for over 50 years. You don't change backups once made. Same fire concerns as most other tape like media. Yes, you have to send it out for developing. If this catches on then low cost, on-site processors will become available. (Keep this idea just between us. I'm already consulting my friend. Her name is Pat. Pend.)

    Excuse me if I sound dumb (not quite my subject this) but would you want to keep a backup tape until it bleeds. I would think that when you want to restore a backup from tapethat you would use the newest one and make sure that you replace your old tapes with new ones regularly. I don't know how long these things last but I am sure the people actually using these things knows about that. I am sure that your idea if 16mm film will also work but can't really comment on that. The most important thing is, however you do it, take your backups offline.

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  • blandry (3/26/2009)


    But if you knew that you would spend say 20 or 30 years in jail for such behavior, wouldn't that at least help deter this kind of thing? I think so, and I don't see any other way to address the problem.

    Yeah, and if we institute mandatory 20 year sentences for drug trafficking, we'll eliminate narcotraffiicking. While we're at it, let's make murder carry a 50 year sentence, then we'll be free from killings!

    I'm not belittling your point. I'm attempting to point out that no matter what you propose as the sentence (the Death Penalty, or affect your parents credit rating!), there will still be people who either think they can get away with it, or who are so angry they don't care. However, I do agree with you that slightly stiffer penalties are warranted. Just as I believe that many crimes deserve stiffer penalties.

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  • Manie Verster (3/28/2009)


    Excuse me if I sound dumb (not quite my subject this) but would you want to keep a backup tape until it bleeds. I would think that when you want to restore a backup from tapethat you would use the newest one and make sure that you replace your old tapes with new ones regularly. I don't know how long these things last but I am sure the people actually using these things knows about that. I am sure that your idea if 16mm film will also work but can't really comment on that. The most important thing is, however you do it, take your backups offline.

    Right. The point is that you do good backup, you test them, and keep them safe off-site. (It is one point.)

    To your question backups have more than one use. Rapid recovery from disaster is one of them. Establishing a reference point in time for historical purposes is another. There are certain mandates for keeping records for a fixed period in time. Electronic records are now a part of many of those mandates. Hence my tirades of the long term storage of magnetic media.

    As far as my 16mm film thing, I was mostly preparing for Wednesday. I have, of course, filed an "in case" process. Kind of like the 6 or more people that already have patents around the world for Interstellar Drive Systems. No joke. You can check the patent databases.

    ATBCharles Kincaid

  • Charles,

    Good points and when you have to keep tapes, like EOY, I'm not sure disk is a great choice. There are already issues with movies trying to keep backups of the new digital technologies. Disks don't last for years, whether spinning or powered down.

    I think tape still is needed. A lot of people that have gotten away from it, I'm not sure you're had the disaster that would surface the flaws in your scheme. Just like lots of businesses haven't needed to restore a db, and don't yet know their backups aren't working.

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