ts-7000
[Top] [All Lists]

Re: [ts-7000] dd and 2GB SD cards

To:
Subject: Re: [ts-7000] dd and 2GB SD cards
From: Mark Featherston <>
Date: Wed, 18 Jan 2012 16:27:34 -0700
Don,

They seem to be the same size between batches, but within the same 
model/brand there can still be size differences.  Unfortunately I don't 
have cards from multiple batches to show as an example.

Best Regards,
________________________________________________________________
  Mark Featherston, Technologic Systems | voice: (480) 837-5200
  16525 East Laser Drive                | fax: (480) 837-5300
  Fountain Hills, AZ 85268              | web: www.embeddedARM.com


On 01/18/2012 04:00 PM, Don Tucker wrote:
> I tried dd'ing without specifying the block size, and had the same 
> problem.  I'm also copying both from and to Sandisk SDs, so unless 
> there is variation in size with the same manufacturer, that does not 
> explain the problem.  I would just resize the partitions on the 
> original SD card, but the big one is JFS, which apparently can't be 
> shrunk (only grown)!
>
> Don
> On 1/18/2012 4:44 PM, Mark Featherston wrote:
>> Don,
>>
>> SD cards vary slightly from card to card.  For example, I have 3 
>> different brands of SD cards here that each say 2GB.  However 
>> according to fdisk:
>> ATP Industrial Grade - 2058 MB, 2058354688 bytes
>> A-Data Speedy SD - 2013 MB, 2013265920 bytes
>> Sandisk SD - 1977 MB, 1977614336 bytes
>>
>> From our experience with SD cards there can be up to a 10% difference 
>> in actual usable disk size even though they are labeled for a 
>> specific size.  All of our software images take this into account and 
>> leave a portion of the disk unallocated.
>> Best Regards,
>> ________________________________________________________________
>>   Mark Featherston, Technologic Systems | voice: (480) 837-5200
>>   16525 East Laser Drive                | fax: (480) 837-5300
>>   Fountain Hills, AZ 85268              | web:www.embeddedARM.com
>> On 01/18/2012 03:24 PM, dtucker wrote:
>>>
>>> I recently went to make a backup of my 2GB SD card used as the 
>>> Debian file
>>> system for my TS-7260.
>>>
>>> dd if=/dev/sdb of=backupfile.dd bs=2048
>>>
>>> The resulting file was 1977614336 bytes. I then attempted to write 
>>> this image
>>> to a new 2GB SD card.
>>>
>>> dd if=backupfile.dd of=/dev/sdb bs=2048
>>>
>>> I received the following error:
>>> dd: writing to `/dev/sdb': No space left on device
>>> 3842049+0 records in
>>> 3842048+0 records out
>>> 1967128576 bytes (2.0 GB) copied, 1950.22 s, 1.0 MB/s
>>>
>>> Why wouldn't the image fit on a new SD card if it could fit on the 
>>> one I copied
>>> it from?
>>>
>>> Don
>>>
>>>
>


------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ts-7000/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/ts-7000/join
    (Yahoo! ID required)

<*> To change settings via email:
     
    

<*> To unsubscribe from this group, send an email to:
    

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/

<Prev in Thread] Current Thread [Next in Thread>
Admin

Disclaimer: Neither Andrew Taylor nor the University of NSW School of Computer and Engineering take any responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU