Is it safer to store your picture collection as .iso's?

Discussion in 'macOS' started by lip5016, Nov 19, 2014.

  1. lip5016 macrumors regular

    Jul 11, 2014
    Hello! So pretty much, I have some large folders, mostly collections of my pictures, videos, music, work projects, important documents, etc.. all on my external hard drive.. Most of the content in these are just things that I want to keep forever, but may be not using very frequently (hoarder of memories lol)..

    I've heard that it's generally safer to transfer large folders with many files and subfolders in .zip and .rar format, as to protect anything going wrong when moving 100,000+ files at once.. Both .zip and .rar are cool, but what about .iso?

    I know that .iso creates a "disk image", like things such as DVD backups, installation disks, etc., so I was wondering if it would be a smart idea to save all of these massive 100,000+ file each collections as .iso format to protect the overall contents..

    I am looking for something that will provide zero compression (no data loss), will not affect the quality of my stored images, or photos, and will be "safer" to use when doing large-scale file/folder migrations or backups..

    What do you guys think?
  2. YanniDepp macrumors 6502


    Dec 10, 2008
    To be honest, I'd just store folders full of image files. When you add more complexity (like storing files in ISOs or ZIPs), you just increase the possibility of things going wrong.

    Say your hard drive gets corrupted and you lose one block of data (a few kilobytes). With a folder full of images, you might lose one image. With something like a ZIP, ISO and DMG, it could ruin the entire file, leaving you unable to extract any images from that file.

    You can get utilities that will safely copy whole folders full of files for backup purposes. Time Machine will do a better job of backing up individual images. Otherwise, if you change one image in a ZIP or ISO, it's going to back up the entire, several-gigabyte ZIP or ISO. If you know your way around a command line, you could use rsync to safely keep a whole bunch of folders in sync. I use rsync to back up several servers with important data at my work.
  3. Fishrrman macrumors G5


    Feb 20, 2009
    I strongly second Yanni's post above.

    If you are just "storing" photos, you want to keep them as "easily accessible" as possible.

    ANYTHING you introduce that reduces accessibility may interfere with "getting to" such photos or data later on.

    You said above that you have large folders full of stuff.

    My suggestion would be to get an external drive (or perhaps even TWO drives), and just "finder copy" the folders you want to preserve to that drive.

    You could also use something like CarbonCopyCloner to copy them over. Everything will be in "finder format" -- easily accessible.

    Also -- if you remove these folders from your "main hard drive", and only have ONE COPY of them on the backup drive, THAT IS NOT ENOUGH (shouting intentional).

    If you have a problem with that one backup drive, you might lose your stuff and be unable to recover it.
    This is why you always want AT LEAST TWO COPIES of anything that's important to you.
    Also, keep the second drive at a different location than the first one, preferably a different building. This protects you against fire, theft, natural disaster....
  4. Alrescha macrumors 68020

    Jan 1, 2008
    If you are concerned about data corruption over the long term, you might consider keeping sets of PAR files (created with MacPar, et al). It does add overhead depending on what percentage of redundancy you choose, but you gain the ability to recover damaged files - even if they were backed up that way.

  5. .X. macrumors member

    Mar 15, 2014
    Quite to the contrary of what some of you say above, I would actually recommend using an archive such as .zip, .7z, .rar and so on for storage.

    The reason for this is that files in an archive have checksums, and there is a test function in the archiver software that can be used to verify the integrity of the archive.

    This means that if you have thousands of files in an archive, and suspect corruption somewhere, you can quickly and easily find out which files have been corrupted (if any).

    If you use a plain image file, such as .iso, you have no way of knowing if the iso has been corrupted, and no way of knowing which individual files have been corrupted without checking them all manually.

    So, a good backup strategy (if you don't wish to use Time Machine on the files for whatever reason) is to archive the files, copy the archives to the backup disk, and perform tests on the archives as often as you deem necessary.

    And as already mentioned by others, you should have at least two backup copies in different locations.


    Forgot to mention, you don't need to use any compression in the archives if you don't want to.

    But except for speed and CPU consumption, there is no disadvantage in doing so. All archivers use lossless compression methods.

    Actually, if we are nitpicking, a compressed archive has a slightly higher probability of surviving data corruption as it occupies a smaller amount of space on the physical media.

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