Mount problem with 64gb microSDXC

Question

I am using a Kingston MMC USB reader with a Samsung 64Gb microSDXC UHS-I card. The first time I inserted it, this dialog appeared: enter image description here

So I searched around and found a similar q/a here; I performed the steps in the answer for the question: Unable to access 64gb volume - Ubuntu 14.04

Now the error dialog does not appear any longer, but the 64Gb card only mounts as 29Gb volume now.

Here is the output of lsusb if that helps:

Bus 003 Device 006: ID 090c:6000 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) SD/SDHC Card Reader (SG365 / FlexiDrive XC+)

fdisk output:

Disk /dev/sdd: 28.5 GB, 28521267200 bytes
255 heads, 63 sectors/track, 3467 cylinders, total 55705600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1           32768   122814463    61390848    7  HPFS/NTFS/exFAT

That's unusual. Did the card work on windows with the same card reader, and writing more than 32GB worked ok? Any changes with a different card reader, in Ubuntu or windows? — Xen2050, Dec 10 '14 at 00:30
Windows showed 26Gb unformatted, so I put the card into a separate reader and it shows 63Gb; its a limitation of the USB device I was using. Thanks for the input guys. — Paul Gregoire, Dec 10 '14 at 01:20
I'll put my questions in the form of an answer then, maybe it'll get selected / check-marked as correct :) — Xen2050, Dec 10 '14 at 02:50
I'm having the same problem with a SG365 based card reader. I think it may not be able to handle more than 32GiB. — jcoffland, Aug 30 '16 at 20:45

score 2 · Accepted Answer · answered Dec 10 '14 at 02:55

That's unusual. Did the card work on windows with the same card reader, and writing more than 32GB worked ok?

Any changes with a different card reader, in Ubuntu or windows?

There are lots of differing card readers of varying quality, some slower, some unreliable, some can't handle SDHC or SDXC (like this one) even though they may advertise they can.

score 1 · Answer 2 · answered Dec 10 '14 at 00:26

1

This looks like a job for gparted - install it if not already done so, unmount the disk (either 1st or when it prompts you to), & see if you can extend it to 64g. If not, it may be a problem with your card reader?

answered Dec 10 '14 at 00:26

Mark Williams

2,580

It turns out that its a limitation of the USB device. – Paul Gregoire Dec 10 '14 at 01:18

GregD · Answer 3 · 2019-03-09T21:11:06.140

This kind of problem occurs with under-performing adapters.

For example, I am see the same kind of problem with a Kingston branded microSD-to-USB adapter which scans as containing a Silicon Motion USB interface chip. In my case, the microSD card is 128GB but consistently shows up as 24.78 GB when this particular adapter is used. It's not a partition issue, obviously, and the problem with this adapter appears on different computers (both OS X and Linux).

To be clear: the Silicon Motion (Kingston) adapter is clearly defective. I suspect it's not able to handle SDXC, or maybe it's too slow for the USB interfaces of today.

Product ID: 0x6200 Vendor ID: 0x090c (Silicon Motion, Inc. - Taiwan) Serial Number: 12345678901234567890 (gotta love that serial number)

-Greg

Mount problem with 64gb microSDXC

3 Answers3

Linked