Drive Snapshot Question

Discussion in 'backup, imaging & disk mgmt' started by n8chavez, Mar 19, 2009.

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  1. n8chavez

    n8chavez Registered Member

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    I am trying to rebuild from a HDD crash. I had a bad drive. I had DS images but they were corrupt, I believe because I needed to use the drive in order to make the ultimate boot disc for windows ISO that contained the images. I couldn't use them. My question is, how do I know if they are valid or not. I validate they right after they are created but that will not help me no if there is an issue when they are on optical disc. I was not able to map virtual drives with the corrupt images. Will this be the case every time they are corrupt, that of course meaning that the opposite would be true. Is that a good rule of thumb.
     
  2. accessalternative

    accessalternative Registered Member

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    Yes -- A good rule of thumb is to manually check the validity of any new image right after it is created, using the View Content Of Saved Disk Image option. If it works, the image is good.

    You're aware that an image is in fact composed of several files: .hsh, .SNA, .sn1 to the very least. If the image is to be somewhat larger - depending on the used space on the partition you wanted to backup, then further .sn2, maybe .sn3 and so on will be added during backup.

    Any of these files, if deleted afterward, will cause the image to become invalid, and unusable.

    For fast restoring, it is a good idea to create and keep images on another partition on the same hard drive, but then one should always copy/paste all the files composing the image on another drive, or on a dvd, in case the whole hard drive gets corrupted in one way or another, instead of only the active partition becoming corrupted.
     
  3. n8chavez

    n8chavez Registered Member

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    Actually that is not the case with my images; I have changed the default settings so that no hash files are created and so that every image is only one file. I do not create incremental images, only full. That being said, thank you for your help. I will be sure to verify that the image can be mapped on DVD from now on.
     
  4. Brian K

    Brian K Imaging Specialist

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    n8chavez,

    I'm confused. I gather the images validated (I think DS calls this "Test") immediately after they were created. Did you write them direct to DVD and they validated on the optical disc?

    Do they validate now? On the DVD or when transferred to a HD?

    How did you determine the images were corrupt?
     
  5. EASTER

    EASTER Registered Member

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    I don't and won't confuse this serious issue but i wanted to share last nights experience with a .SNA image that was nearly forgotten by me lodged on a DVD. I inserted the DVD and opened DriveSnapshot to see if i could mount it virtually or not being so old by now.

    Well. It mounted the .SNA while still on the DVD and opened up fine. Even though it's supposed to be write-only, i copied some files from it to my hard drive anyway.

    DS has to be the most versatile and dependable imaging app i think i ever encountered. Next step is going to be to restore it to a hard drive which i don't have any concerns all will go well.

    I dunno what happened above but i NEVER validate a DS image beause it's never failed me either on DVD or a Hard Drive partition. Perhaps the validate procedure made for that issue?

    I do hope it turns out in your favor regardless of what you're experiencing ATM.
     
  6. n8chavez

    n8chavez Registered Member

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    I hared rebuilt my drive, which was not easy seeing as how I lost everything. I assume my PC is like the majoity here in that it is majorly customized at tweaked. Nothing is default. My system is rebuilt better now than when the original image was created. I can create a full system (c:\) in 2:15. I have never seen any other imaging application that can touch that. It also have AES256 encryption. For me DS is invaluable. I like the fact that it is extremely small and is portable.

    But back on the original topic. I prefer to use the UBD for Windows method because it allows me to put images of c:, d:, and my flash drive on the same DVD (singular). I cannot do than any other app. That means that I have one disc for recovery. At least that is the way it is supposed to work. I believe my original images were corrupt because of my HDD issue(s); I was experiencing the infamous clicking sound for a while before the crash. The images must have become corrupt when I created the UBD iso. At least that is the only thi ng I can think of that might have cause the issue. I know the images were corript because I received numerous header error when I tried to restore and mount the drive.

    As I said, everything runs perfectly now; all my images 'test' okay. I was just looking for a way to test the burned images in hopes of not ever repeating this whole mess. It looks like if I try to mount the burned images, and that process is successful that will be a method of 'validation', correct?
     
  7. Brian K

    Brian K Imaging Specialist

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    Validation is not a test of software reliability. It is a test of whether your hardware is able to restore that image. For example, bad RAM can lead to validate and restore failures. Validation should be done on the image at "regular" intervals during its lifespan. Not just immediately after it has been created. "Disk rot" (DVD and HD) can also lead to validate/restore failures.

    In this forum we've seen several threads where the user didn't validate an image prior to the restore process. The restore deleted the target partition (as it is supposed to do) and then failed to restore the image. This left one member with no recoverable OS as he had no other images.

     
  8. EASTER

    EASTER Registered Member

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    I don't deny it's useful purpose, i have validated before untill blue in the face, then began bypassing validation. Result was no change, no issues, no problems. Thats what i base my practice on no validations with DS because it's more reliable then plenty of other imaging apps i've used before.

    It's still at 100% for me with no distractions either imaging or restoring. Theres a lot to be said for an imaging app with that percentge of success rates.
     
  9. Brian K

    Brian K Imaging Specialist

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    I've never used an unreliable imaging app. They are all 100%. In testing, using various apps, I've restored thousands of images without a validate or restore error. Yet I still validate every image before it is restored. I'm more concerned about hardware issues preventing a successful restore. It doesn't demonstrate lack of faith in your software if you validate an image.
     
  10. Osaban

    Osaban Registered Member

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    Brian K, what you're saying is very interesting indeed: basically having a "good image" doesn't necessarily mean that it will restore your system for sure, as the hardware might fail to do so for all sorts of reasons.

    My question is if the hardware is responsible, does that mean any other image that one might have is unusable? If that's the case, is reinstaliing Windows the only solution?
     
  11. nexstar

    nexstar Registered Member

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    Guilty as charged :oops: . Having pontificated here about the dangers of restoring an unverified image over the very data it was created from.....I did exactly that.

    I had a system with one drive and two partitions and the system was freezing for long periods. So I made a DS backup of the system to the second partition and decided to try a repair install of XP.

    This didn't go well and I ended up with a non-booting system. Feeling smug that I had my backup, I then went ahead and restored it without verification. It failed to restore and, by then I had wiped my original data.

    Of course the hard drive turned out to be faulty but (and here's the relevant bit for n8chavez) I could mount the image as a virtual drive ok. There were some corrupt files but the vast majority were ok and I could retrieve all the documents without a problem.

    So no, being able to mount a drive and explore it is not as good as a full verification. I see from DS v1.39 that there is now a repair option to allow you to mount damaged images to retrieve files. The command line is:
    c:>snapshot x:\DAMAGED.SNA --repair:Y:\REPAIRED.SNA

    I wonder if this is default behaviour in the gui now and may be why I could mount it ok. Have you tried the latest DS version on your damaged image, n8chavez?

    I agree with Brian that it is not a slur on the software to verify as it is as verification is as much about the hardware and, as in my case, if you are needing to restore an image then there is a higher probability that faulty hardware has got you to that point in the first place.

    Also, I'm getting a Nod32 trojan warning on the snapshot.exe file and the setup file when I try to download them from the www.drivesnapshot.de site. Does anyone else get this?

    Graham
     
  12. Brian K

    Brian K Imaging Specialist

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    If you fix your hardware, replace the bad RAM or data cable, etc, all images should restore. The images themselves are probably OK. Especially if they passed validation at an earlier stage.
     
  13. MerleOne

    MerleOne Registered Member

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    I usually don't validate .sna images, I just open them and mount the virtual drive, then perform a chkdsk, it's quick and if successful, it means the image is most certainly valid.
     
  14. n8chavez

    n8chavez Registered Member

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    Does Drive Snapshot backup and restore the MBR when imaging and restoring active partitions? I ask because there is little documentation of that matter. I know that it is possible with the frontend utility but I do not know about DS by iteself.
     
  15. Jo Ann

    Jo Ann Registered Member

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    DS does backup the MBR but does not automatically restore it, as there are situations when you might not want to do that. DS will restore the MBR if you 'request it' to do so.
     
  16. n8chavez

    n8chavez Registered Member

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    As far as I know, the MBR can only be restored using command line. Is that true? If it is then that doesn't help me, as I use the DS executable (I do not use the dos disk).
     
  17. Brian K

    Brian K Imaging Specialist

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    n8chavez,

    I'm still confused. What about your old backup images? I'd expect that you have images on DVDs going back months.
     
  18. n8chavez

    n8chavez Registered Member

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    What's there to be confused about? The image I had was corrupt, and therefor unusable. I create images every month and throw away the older ones as soon as I do.
     
  19. Brian K

    Brian K Imaging Specialist

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    Big mistake.
     
  20. Jo Ann

    Jo Ann Registered Member

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    No, that's not true; the MBR can be restored from DS' Windows GUI. Just right-click on the HD1 box and you will see that option (btw, I don't use the DOS disk either). ;)

    JA
     
  21. n8chavez

    n8chavez Registered Member

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    The rearview is always 20/20. What are the changes my images would become corrupt while building an ISO?
     
  22. Brian K

    Brian K Imaging Specialist

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    Unfortunately it's nothing to do with hindsight. Just standard practice.
    We should keep several generations of backups. Kept on different storage media. At least one copy should be stored off site.
     
  23. bgoodman4

    bgoodman4 Registered Member

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    Clearly the chances are not zero or there would not be a problem now. I learned this the hard way a number of years back and it was a lesson that I will never forget. More recently I had the experience of an external drive failing just when I needed it. It was the drive that I store my daily images on. Thats 30 days worth of images. Fortunately I had images on other drives (one off site and one on site). They were not daily but as I upload my critical files to a storage service (iDrive) daily I was able to recover fairly easily. Took a bit more time than simply restoring to yesterdays image (I was 4 days out) but a heck of a lot better than starting from scratch.

    Just a suggestion but have you tried to recover and or fix the data from the disk? There are programs out there that claim to be able to do this although I have never tried them.

    Good luck with this, I have my fingers crossed for you.

    PS: I am actually (based on reading these forums) going to get a 2nd imaging program and create even more images "just in case",,,,ya, I know, paranoid but ...... I am currently using ATI for both my PCs and have a copy of RollBack Rx on my tablet so I will use RBs imaging tool for that one but would like a 2nd set from either Paragon or Drive Snapshot to supplement the TI images. Reading the ATI forum has left me feeling vulnerable.
     
    Last edited: Mar 21, 2009
  24. EASTER

    EASTER Registered Member

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    Lucky for me i guess that old DS snapshots are as good as GOLD, even when not verified. I turned loose a very destructive malware that made so many changes i couldn't boot no more. No amount of FIXBOOT/FIXMBR would help, it would just begin booting and then WHAM! return to sender as in square one. I do my research without virtualization so i use a single hard drive with 2 partitions so it fell to me to use DS to do a complete partition restore and like nothing ever happened, it's right back in business again.

    This DS app is already done for me what many otherimaging/restore apps couldn't always do, and the if there is such a thing as corruption, it absolutely must be either in the hardware or some software/malware conflict because this Super imager is still batting 1,000 for me and is still not EVER failed me. It just goes about it's task 4 me as sure as the sun rises and the moon goes round.

    Not bragging, just completely shocked! but pleasantly and thankful so that some apps are this dependable.
     
  25. dalidstone

    dalidstone Registered Member

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    I have been trying to find a simple solution for users trying to solve back up problems. I have found Drive Snapshot fulfills this requirement. But I have also encountered problems occaisionally downloading with Eset A/V or Smart Security gives a warning, but I have always found a clean source elsewhere on the net.
    Always verify any image created, and always make 2 copies in different places. No good imaging to another partition and then the drive dying, cos when the drive dies its all LOST. External drives are now getting so cheap even in these hard times it pays to have 2.

    I now have a problem specifically with a Compaq Presario C300 laptop refusing to mount any snapshot file but having no problems when trying with Acronis TrueImage Images.
    I have tested with a different PC and no problems with any of the sna's. Any ideas would be useful as I am running out of them.
     
    Last edited: Apr 2, 2009
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