I have a galaxy S3 with a 32gb class10 sd card.

Unfortunately I experience the SD card unexpectedly removed - Preparing SD card phenomenon all the time. The card works ok as long as it is being used: I watch videos, mp3 etc, even on pc.

I tried formatting a couple of times and I also checked on other S3 phone which presented the same problem. I checked a 16 GB class 10 card on my phone which worked ok!

I read somewhere that this is a JB problem and that I should wait for 4.2 (I'm on 4.1.1 now)

Another solution explained that I should root my phone and do this:

Edit files in the folder /sys/devices/virtual/bd i/179: 0/read_ahead_kb by pressing and holding the read_ahead_kb then choose open in text editor.

Note: Other phones don't have 179:0.. but is ok 179:8 Replace the numbers in it from the default (128KB) to 1024 / 2048 / 4096 (according to taste max = 4096) and then save and exit.

What are your thoughts? is it JB or the Card?

I should also mention that the removing/rescanning my card is killing my battery very fast.

  • 2
    First thoughts: Please improve spelling. I tried to fix most of it already, but for two paragraphs I had no idea what it should like ("Edit files in folder..." and the following). It's not clear to me what those mean. Would you please edit/update that part?
    – Izzy
    Commented Jan 4, 2013 at 13:26
  • when you formatted the sdcard, did you format it on the device or did you format it from a pc? Commented Jan 4, 2013 at 14:34
  • i am also not quite sure what the guy meant... im quotinig someone else
    – krasatos
    Commented Jan 5, 2013 at 14:20
  • My thought: It's the card and/or Samsung's firmware. I personally have a Galaxy S2 with a 32GB card (that runs CyanogenMod aftermarket firmware, i.e. Jelly Bean 4.1, for some days now CM10.1/Jelly Bean 4.2.1). Never experienced that problem here (it's only a class4 card though). Regarding the battery problem on rescanning: Well, depending on the fill level, Android has to sift through a massive amount of files/data.
    – ce4
    Commented Jan 5, 2013 at 14:35

1 Answer 1


Sounds like an SD card problem to me. I've experienced similar problems a few times over the course of the years -- a card that has worked ok for some time has started to get "ejected" by itself. Changing the SD card has always solved the problem. .. Hmm. Except once but that phone turned out to be a very problematic case in a number of ways.

So, try out changing the SD card, I would suggest.

  • That's what I did, after some time, tried another sd card and it worked ok
    – krasatos
    Commented Jun 9, 2015 at 20:16
  • Glad to hear @krasatos . Now, if you wouldn't mind marking my answer as The Chosen One (or what ever the heck it's called in here) I would appreciate that (as it would give me some reputation points -- and remove some of the dorky limitations of what I can(n't) do in StackExchange. Thanks.
    – jaakkoh
    Commented Jun 9, 2015 at 21:02

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .