Before I made multiple cloud accounts available to backup my Mac, running OS X El Capitan, I saved every file in All My Files onto a 16 GB external SD card.

I noticed that every few days everything on the SD card would seem to disappear. Is there any explanation that could be had for this?

  • 3
    The prime explanation would be the SD card itself. I wouldn't trust one to keep anything important on, ever. I get through thousands of them for work & the fail rate is alarming.
    – Tetsujin
    Dec 17, 2015 at 16:21
  • 1
    I've never had this problem before, actually. Then again, I'm not usually trying to back up my entire computer on one, just selected files. Could that be that problem? It's 16GB, so I thought it'd be enough room. Dec 17, 2015 at 16:42
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    It's not really how much room they have. My guess is something has triggered the firmware write-protect, which can sometimes look like a file has been written, but it really hasn't. Eject/insert & it's 'just gone'. Once that happens, the only thing to do is get all your data from it, then throw it in the bin. It's worth trying to format it once, but if that fails - the bin awaits.
    – Tetsujin
    Dec 17, 2015 at 16:46

1 Answer 1


Backing up specific folders instead of copying the disk images (I realized that's what 'All My Files' consists of) has allowed me to make permanent backups with different services and devices, including my SD card.

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