All Data lost with iMac, 4 disk Mac Pro in the Mail

Discussion in 'Mac Pro' started by skyneedle, Nov 28, 2006.

  1. skyneedle macrumors newbie

    Oct 28, 2004
    Hi all. I recently lost all my data (music, pictures, tax returns, resumes, everything) on my iMac which was not backed up. (I know) I have sworn that this will never happen again and my Mac Pro is on its way with 4 250 GB hard disks. I will use the Mac for Aperture and general use. No video editing. My question to the forum is:

    What is the recommended configuration of these four disk to ensure that I never lose my data ever again?

    I'll use the OS X software RAID for any RAID configurations. I've read the forums and it seems the general best practices advise against a RAID 0 for the startup volume. I'm thinking RAID 1 (mirrored) for the startup volume and data storage. Then using the third disk for Apple Backup based backups with weekly fulls and daily incrementals. I'm not sure what to put on the forth disk. I value stability over performance. Thanks in advance.
  2. THX1139 macrumors 68000


    Mar 4, 2006
    This is probably not the answer you want to hear, but I want to remind you that data such as resume's, tax returns etc., easily fit on CD/DVD. The reason you lost your data was not due to what machine you were using, it was due to laziness. Buying a MacPro isn't going to save your data if you don't come up with a fool proof method of archiving. Okay, so your new MacPro has 4 hard drives. How is that going to save your data if you don't take the initiative to back it up? I'm talking about taking it OFF the computer and putting it in a separate location. Important data needs to be stored in a separate location in case of fire or theft. Having your data stored on separate drives on the same computer is not going to help you if you lose the computer!

    I suggest important data be burned to DVD or CD and stored in a safe location. For example, whenever I'm working on a project I usually store copies of the work on an external drive AND burn to CD's that I put under the seat in my car or leave at a friends house until I finish the project. If you have large files that won't fit on dual layer DVD's, then maybe you should buy an external storage drive to back it up to.
  3. ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    Take this advice from someone who's done this kind of stuff for a living...

    The rules for keeping your data are:

    1) Data should exist in at least three copies. 1 and 2 are NOT safe 3 is the minimum Note that this means if you use re-writable media for a backup the old backup is overwritten and does not "count" while a backup is in progress. You need four copies if you plan to overwrite a backup.

    2) At least one of the three copies must be stored at differet location in another building

    3) you must keep a HISTORY of your file system. Perodic full copies are not effective. Reason: If a file is lost and then you make a full copy of your system now your backup has a lost file too.

    4) use any media type you like. Portable hard drives, CD or DVD ut don't expect any of this to last a long time. It will all die in a few years. you must rotate new mdeia into your system.

    Why not just use RAID? Because the #1 reason for lost data is operator error followed by a software screw up and theft and fire and raid don't help with either of these.

    What do do? Make two copies of your data. First copy everything to DVD, CD or hard drive and take it to your office (assume you do not work at home) then make another copy and put it in a small fire safe in your house. (Yes a waterproof fire safe. Buy one for under $100
    then repeat the above on a schedule Just let those backups pile up for a while and if you run out of space toss a few of the older backups OK so now you have a bare minum system going.

    Next you can attach a good sized external drive and program a daily incremental backup. If you have a Mac Pro I gues you could use an internal drive for this.

    Lastly you primary storage could be a RAID system if you like

    Use any system you like but do remember to (1) three copies minimum - even durring a backup and (2) data is kept at two geographic locations (3) yu must archive NOT just the current state of your system but also older snapshots of it. Any system that does al this will serve you well. Conversly any system that breaks on of the above rules will fail and you
    WILL loose data again

    You do not need fancy software. Fire up a terminal and type "man dump" (without the quotes) the man page will say "Dump examines files on a filesystem and determines which files need to be backed up....." Lots of good free software available, some already on your Mac.
  4. coolcorgi macrumors newbie

    Dec 1, 2006
    More clarification for a newb please.....

    Thanks ChrisA above. Could you please expound upon certain aspects/elements noted below.

    the old backup is overwritten and.....???? - "does not count while a backup is in progress. You need four copies if you plan to overwrite a backup" - ????.....

    you must keep a ..... ???? - "HISTORY of your file system. Perodic full copies are not effective". - ????..... Reason: If a .....???? - "file is lost and then you make a full copy of your system now your backup has a lost file too" - ????.....

    use any media type you like. Portable hard drives, CD or DVD ......???? - "but don't expect any of this to last a long time. It will all die in a few years." - ????..... you must rotate new mdeia into your system.

    Next you can attach a good sized external drive and .....???? - "program a daily incremental backup." - ????..... If you have a Mac Pro I gues you could use an internal drive for this.

    Lastly you .....???? - "primary storage could be a RAID system" - ????..... if you like

    WHAT DO YOU MEAN BY "PRIMARY" - I assume "RAID" is software?

    you must archive NOT just the .....???? - "current state of your system but also older snapshots of it". - ????.....

    Sorry for not knowing how to use the "quote" feature while replying. Hell, I tried adding a smilie the other day, got frustrated trying, and had to accept defeat. This stuff can humble you fast! I don't post much. I read, read, read. Without this forum, I'd be confined, stuck playing "space invaders" eternally.

    I'm hungry, willing and trying.

    Thanks tons,
  5. jsw Moderator emeritus


    Mar 16, 2004
    Andover, MA
    While I agree that ChrisA's methods are pretty bulletproof, your needs might be much less than the ones he anticipates. Since only certain files on your HD need backed up, I'd buy 2-3 cheap external drives, and back up your critical files each night (this can be automated). Swap the external drive every few nights or once a week, and keep a relatively recent one elsewhere (in case of accident/theft/etc.) - i.e., rotate them out of your house or at least into somewhere safe regularly.

    Could you lose stuff? Yes. But not all of it, and rarely anything important. And this is much easier than using CD-R's or DVD-R's... but I'd still use those to make immediate copies of your really critical data.

    You can of course be very thorough with your backups, but the multiple-external-drives approach is easy, fairly automated, and will "only" cost a couple hundred dollars for peace of mind.
  6. trainguy77 macrumors 68040

    Nov 13, 2003
    Well since you are ordering 4 drives you could run 2 mirrored sets. One backed up to the other set. However, I would still recommend a external drive so in case user error occurs you won't lose your files. Yes this is not bullet proof. But its better then I do. I just use an external drive.:D
  7. Richard Flynn macrumors regular

    Sep 4, 2006
    Hi coolcorgi. I thought I'd address each of your queries in turn so that you're completely clear. Sorry ChrisA if you think I'm stepping on your toes.

    Two things to point out: first, I realise that you're not the Original Poster for this thread, so I'm not going to assume that you're in exactly the same position as skyneedle; second, ChrisA's proposed system is admirable and very thorough, however many private users would find his system overkill and too pricey for their needs. I'm not saying that that's your position, however, just wanted to warn you.

    OK — point by point:

    So, ChrisA is advocating having at least three copies of your data: the primary copy (the original on your computer's hard disk) and two backup copies. However, he suggests that if you're using a rewritable medium to perform your backups (e.g. Hard disks, DVD-RW) then while your computer is actually making the backups, only two complete copies of your data exist (the original and the other backup). This, he suggests, isn't suitable (since you no longer have three copies of everything all the time) so you need to have a fourth copy of your data to satisfy the three-copy minimum (original, two backups and the third backup being performed).

    If you use software like the excellent SuperDuper, your backup system will be the software making a mirror of your main drive onto another hard drive: the backup copy (copies) would be a 'snapshot' of your main drive at the time the backup was made. However, what if you deleted a file from your main drive, then performed a backup, and then realized that you needed that file again? The file would have been erased from the backup as well, since the backup copy is simply a mirror of your main drive at a given moment in time. However, if you use software such as that formerly known as Dantz Retrospect (equally excellent in my experience, but it can be complicated and can be expensive, and others loathe it), it keeps archived copies of your data in your backup system, with the result that you can go back to a version of a file from several generations ago, even though you may have made several backups since then. Doing backups like this obviously requires more space for your backup, however.

    In other words, all media die, whether they be CD/DVD or Hard Disk. Therefore you should work out your own 'media rotation' cycle so that you replace old disks in your backup set before they have a chance to die on you. A dead backup is a worthless backup, after all!

    An 'incremental' backup is one where the backup software examines your main drive and only copies the files to your backup drive(s) which have been changed since the previous backup. If you 'program this to happen daily', then it would happen automatically daily so that your backup set is always up-to-date within a margin of 24 hours. An incremental backup is very useful when used in conjunction with software like Dantz Retrospect, which I mentioned before, since it is effectively 'archiving' previous versions of your files.

    Oh, boy, RAID, joy. OK — RAID stands for 'Random Array of Independent Disks' and can either be controlled by software (your operating system — RAID support is built in to OS X) or by a hardware card. RAID is essentially a system whereby multiple physical hard disks appear to the OS as one contiguous drive. There are different setups for RAID, although two are the most common: either you set it up so that streams of data are split up and written to multiple disks, with the result that your drive-access time is much faster (since multiple disks are doing the work of one drive)—this is called 'striping', since data is written as 'stripes' across many disks; the other common RAID system is 'mirroring', where each of the disks in the array stores exactly the same data, with the result that if one disk goes bad, then the other disk still has all your data; you can drop in a new disk to replace the failed one and the data is automatically copied to it and everything is kept in sync. This is not a suitable replacement for a backup, however (for the same reason that just overwriting snapshots is not a suitable backup).

    By 'Primary' I think ChrisA is suggesting that you could use a RAID system as your main drive.

    You can read up on RAID on the Wikipedia, and there's lots of other information about it all over the Web.

    This is going back to the point earlier about not just making snapshots of your data, but keeping incremental versioned backups. In an ideal backup methodology, you would be making backups (at least two, if not three, remember!) with a versioned incremental system where there may be multiple versions of any given file included on the backup disk. Then, periodically, say monthly, you would make a complete snapshot of your drive on that day and store that on removable media such as DVD-R; that way you would build up an archive over the years of the way your system looked month by month.

    This is all pretty complicated stuff. Effectively, you need to work out a backup system that has enough inbuilt 'redundancy' to cover you if any kind of disaster strikes (hard disk failure, theft, fire, storm: therefore it makes sense to keep copies of your data offsite). I hope I've been of some little help, and haven't served only to compound your confusion!


    PS I'll let someone else explain how to do comments in BBCode. I didn't want to keep all the fun for myself.
  8. coolcorgi macrumors newbie

    Dec 1, 2006
    Thanks Richard! Awesome explanation and help....

    Wow! Really appreciate your extensive, well written explanation and response Richard! That helped tremendously.

    It's all becoming more and more clear. I've only been tinkering, using computers (windows) for about 4 years now; so I have "beaucoup" (plenty) posts, like yours, to read, decipher and interpret! But thankfully, it's all here. Via very intelligent members with tons of experience who are quite able and often willing to share and assist ignorant newb's like me.

    I've got tons of "catching up" and learning to do, for it is abundantly clear that the digital, computer, information & internet "arenas"....... could quite literally mean the difference between life/death. Hate to put it that way, but I do believe there will eventually, essentially be 2 classes. Those connected and capable, and those not. Hell, I think it's already like that!

    Irregardless, I really like working and spending time on-line and on-board my computer. I desperately want/need to know and become reasonably proficient in the above arenas. I never would have guessed or thought that I would have enjoyed and taken to it so. But I have and I'm in. For the last 1.5 years, I spend between 6 to 12 hours a day on the computer. I'm probably not that "inclined" with this stuff, either; but that's just too bad. Cause I'm gonna get it, painstakingly if necessary.

    Gotta go now, but will be back needing purchase advice and help pronto; as I'm going to invest in a Macintosh ASAP. I'm going to spare no cost in getting exactly what I want and need! I've got the ducats and I'm excited, but am being patient. For in my opinion, I lack the sufficient knowledge to intelligently, wisely select. But I'm getting close.

  9. jaguarx macrumors regular

    Jan 5, 2003
    Bingodisk might be of interest to you. If you're serious about backup, as other people have said, you need something offsite.
  10. ero87 macrumors 65816


    Jan 17, 2006
    New York City
    OP, how old was your iMac? Should I be considered about my 18-month-old iMac losing all of its data suddenly?

    I don't back up any of my files- why should I? It would be really bad to lose all my photos/songs, but why would my harddrive just fail?
  11. trainguy77 macrumors 68040

    Nov 13, 2003
    It has nothing to do with age. Actually I find newer drives die more often. I lost a drive in a emac after only 8 months. You should backup all your data regularly. People rely on the it won't happen to me mentality too often.
  12. ero87 macrumors 65816


    Jan 17, 2006
    New York City
    I've never had a PC harddrive fail on me. Are Mac harddrives more susceptible to failure?
  13. trainguy77 macrumors 68040

    Nov 13, 2003
    they are identical to PC drives except sometimes for the IO used but most of the time the same. Same brand names even. For example my mac pro drive is a seagate. It just means either you have been lucky or not owned alot of PCs.
  14. QCassidy352 macrumors G4


    Mar 20, 2003
    Bay Area
    indeed. my ibook's HD went after 8 months also. Fortunately I had JUST bought a macbook to replace the ibook, so I had a full backup of everything. Had the drive died 2 weeks earlier, I would have been royally screwed. Now I keep better backups (but nothing as elaborate as what chris suggests above!). :eek:
  15. ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    First off, Macs and PCs use the same drives so the failure rates would be more or less the same.

    It's all just luck. The drives are designed with a given lifetime and many will last for twice as long as their designed in lifespan and some will last about 1/4 that long and some are dead right out of the box. But on average you can plan on a drive to last about 5+ years before it fails.

    If you only own one or two disk drives then you will only see one or two failures in a five or six year time span. But if you own 100 drives you should expect to see 100 failures per 5 or 6 years or more than one a month on average.

    The chance of a drive failing does depend on it's age. They call it a "bath tub" curve. There is a high chance of failure when the drive is very new but if it passes this initial period it has a low chance of failing but then as it ages the chance of failure slowly raises until it gets very old and then again has a high probability. During the drive's mid life it is quite reliable but there is always that 0.5% chance. There is a reason for this. Manufacturing defects cause the early failures. If these are no defects then usage causes the parts to age and wear out until finally they fail

    Light bulbs are the same way. New ones some times fail, they always fail given enough time. Disk drives are a lot like light bulbs.
  16. ChrisA macrumors G4

    Jan 5, 2006
    Redondo Beach, California
    If you don't back up your stuff it is not a matter of if you will loose it all but when you will loose it all.

    Why will the drive fail? It's a mechanical device with moving parts. Given time all mechanical devices fail. Also this is a notebook what if you drop it? What is someone steals it. What if it is plugged into the wall and lightening strikes a utility pole a mile or two down the road? What if a software error corrupts the file system? There are about 100 ways to lose data. What if there is a fire, flood or earthquake and the computer is destroyed? In time one of them will happen.

    The basic rule is that there always needs to be three copies of the data on three different physical media and located in two different geographic locations. that's the minium to ensure the data lives for many years.
  17. MacBass macrumors 6502


    Aug 12, 2005
    La Crosse, WI
    I personally discourage the use of RAID 0, because with SATA drives, the transfer rate is much faster than old PATA drives. You have 2 HDD's now with your data, and if one drive fails, you have no hope of recovering your data. We had a RAID 0 little network server die on us here at school. One drive's controller board fried and the data was unrecoverable.

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