I am trying to format a micro SD card from Ubuntu to use it for flashing ROMs to my tablet. When I get an adapter ( I tried lots ) from micro SD to SD and plug it into my SD slot the card shows up, but when I click on it in Nautilus I get the message:

                         Unable to access "32 GB Volume"

                         An operation is already pending

Also it disappears and appears back again about every 5 sec.

I'd really like to get it working, because it's a very fast card that I also need for my 360 camera and drone, because they also need very high write speeds. In Gparted it shows up as /dev/mmcblk0 which I obviously don't have that many devices I only have a Hard Disk and a MSATA SSD, so /dev/sda and /dev/sdb. When I try to format it in Gparted it says input/output error, and sometimes on the start of Gparted I see /dev/mmcblk0 is not a directory.

Thanks in advance.

  • 7
    Please provide the output of dmesg when inserting the module. It may be a faulty reader or a faulty card.
    – vidarlo
    Aug 17, 2017 at 11:48
  • 3
    Do you have the read only switch set on the SD card? Aug 18, 2017 at 2:36
  • 2
    /dev/mmcblk0 indicates that the card is identified not via USB but via an internal card reader. Did you insert it into an internal card reader and then unplug it without unmounting and after that connect it via an[other] adapter again? It is also possible that the card has the exFAT file system, which is a proprietary file system own by Microsoft. In this case you can install special tools to read/write files. The card could also be failing, but there are many things to check or fix, that might bring it 'back to life'. Anyway, please specify details about the card: brand name, model, size.
    – sudodus
    Aug 19, 2017 at 2:58
  • The following link might help you analyze the problem and try some methods, that might bring it 'back to life', askubuntu.com/questions/144852/…
    – sudodus
    Aug 19, 2017 at 3:08
  • @MihailMihov, Please specify details from dmesgand about the card: brand name, model, size, maybe more details, and it will be easier to help you.
    – sudodus
    Aug 24, 2017 at 12:55

2 Answers 2


It sounds to me like you have a hardware problem. What I would suggest, is to get a SD to USB adapter and try that. It should solve your problem for now. If that doesn't work it is a problem either with the SD card, or the software. In this case the SD card is the more likely candidate. In which case fixing it is nigh impossible. So yeah. Hope this was helpful!


It does sounds like it could be a hardware issue like most people have said, make sure the lock in the card is all the way to the unlock position.

I always had better luck formatting SD cards (and pretty much with everything in Linux) through the command-line. If you don't have any information of value on the card, I would try to format it from command-line. You can follow the steps from here:

Find your card name with lsblk, which in your case sounds like it is /dev/mmcblk0.

I usually use fdisk but parted will do too: sudo parted /dev/mmcblk0

(parted) mklabel msdos

(parted) mkpart primary fat32 1MiB 100%

(parted) set 1 boot on

(parted) quit

sudo mkfs.vfat /dev/mmcblkp1

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