I bought a bigger microSD card for my Samsung Galaxy S7 Edge. I took out the old card and copied its content to a folder on my PC, via a card reader. Then I put the new card in the reader, formatted it and started copying the data back onto it. One rather irrelevant .jpg file was signalled as damaged, so I skipped it, then some folder required admin rights to be copied, so I clicked the "continue as root" button. So far so good. But finally a folder named "cache" couldn't be copied or skipped, and the only option I was left with was to abandon the whole copying process. I searched my backup folder for "cache" subfolders and there are quite a few of them, but all are buried deep in the recesses of the directory tree, so none of them is THE Android cache that I hear a lot about when googling for a clue. Any ideas what it is I'm up against, and how to solve it? My PC is running Windows 10. TIA!

1 Answer 1


If your Windows ask you for admin permissions something is wrong - this should never happen as you just copied it from the other SD card.

Anyway copying and SD card file by files is IMHO not a good idea because the Windows Explorer does usually hide certain files.

Therefore I recommend to use a backup tool or alternatively use a compression program like 7Zip/WinZip/WinRAR and zip the whole source SD card to one file on your hard disk.

Then switch to the new SD-Card and restore the backup respectively decompress the created archive to the new SD card.

Edit: Note that a lot of SD cards on the market are "fake SD cards": Their controller has been manipulated to make the SD card look larger than it is (e.g. the card has 16GB flash memory but tells the Smartphone/PC it has 128GB). Writing to such a card will earlier or later end in a total disaster. Therefore I strongly recommend you to test any new SD card before using it. One of the best tools I know for doing so is a small Windows tool named h2testw (Language German and English). It writes files with a special pattern to the SD card until it is full and then reads it and tests if the pattern of every file is correct.

  • Up voted. You may also like to mention that dates of files are preserved using zip method. That would be much needed for photos for instance
    – beeshyams
    Commented Dec 2, 2018 at 0:47
  • Thanks for the reply. I found a software called EaseUS Todo Backup Free. After one failed attempt, it claimed to have successfully backed up the original card. Then I put the new one in the reader and told the soft to restore the data onto it. It started doing so in "disk-partition mode" or something like that, and was apparenty going to recreate the exact structure of the old card, including the same capacity - which would obviously make the whole investment pointless.
    – Xirdal
    Commented Dec 3, 2018 at 6:12
  • I hope the errors are due to botched formatting of the new card, and now I'm in the lengthy process of hard-formatting it (at 512 GB it will take a while). Stay tuned....
    – Xirdal
    Commented Dec 3, 2018 at 6:44
  • @Xirdal If your new SD card makes problems it may be defect or forged (see the last section I just added on that topic).
    – Robert
    Commented Dec 3, 2018 at 8:17
  • The phone is my wife's and she went to see her folks without me having enough time to fully format or test the new card. There is a gadget-expert brother-in-law over there who may be able to help; if he doesn't, I will probably be back with a follow-up to the story. Thanks again for all the replies.
    – Xirdal
    Commented Dec 6, 2018 at 7:06

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