home | list info | list archive | date index | thread index

[OCLUG-Tech] how to determine the *usable* size of an SD card?

  • Subject: [OCLUG-Tech] how to determine the *usable* size of an SD card?
  • From: "Robert P. J. Day" <rpjday [ at ] crashcourse [ dot ] ca>
  • Date: Thu, 19 Jan 2012 14:48:56 -0500 (EST)
  over the last day on the beagleboard list, there was an animated
discussion that touched on the fact that some "dd" copies to SD cards
was failing since the actual capacity of the SD card was noticeably
less than advertised.  as in, trying to write a 4G image to an
allegedly 4G SD card failed, "no space left on device".

  is there a utility in linux that will tell me that *real* capacity
of an SD card if i pop it into the SD slot?  if i write an image to an
allegedly 8G micro SD card and pop it into my beagleboard, and stop in
u-boot, what i can do is:

# mmcinfo
Manufacturer ID: 27
OEM: 5048
Name: SD08G
Tran Speed: 25000000
Rd Block Len: 512
SD version 2.0
High Capacity: Yes
Capacity: 7969177600     <--- AHA!
Bus Width: 4-bit

  that's *clearly* less than a true 8G.  is there a way to see that in
linux?  thanks.



Robert P. J. Day                                 Ottawa, Ontario, CANADA

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday