Re: DD problem

[Eric Blake]

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[please keep the list in the loop.  Also, top-posting is frowned on in
technical lists, so I've reformatted your mail]

According to Douglas Ritter on 3/27/2009 10:41 PM:
>>>>> I'm having problems to use the command DD on my pendrive with
>>>>> 2052547072 bytes (not formatted). The program stops answer the
>>>>> command after write 1,5GB and still reading the device perpetualy.
>> 
>> Meanwhile, in regards to your question, we need more details before we
>> can
>> offer any assistance.  What command line did you issue?  How do you know
>> it is stuck in a read loop?  What OS is this on?  Have you tried strace
>> (or its equivalent) to see what the system calls are doing?
>> 
> 
> I use
> 
> # dd if=/dev/sdb of=/home/pendrive.img (for a example)
> 
> it starts but dont stop nevermore. So I reset my computer and when Linux
> (Debian Lenny) back, I go to see what it did and I found a file with 1,5
> gb. I did already wait more than 40 minutes and get same thing. If I try
> stop the process with ctrl + z it wrote in my screen "^z" and dont stop it.
> 
> if /dev/sdb is output and input is another thing it does not work too.
> 
> But, using Slackware 12.2 I did can to use dd with success. I did get
> this error too in Kurumin Linux (a brazillian linux based on Debian
> etch) and another based debian distributions.

Have you checked which version of dd each of these machines is using?
What about the Linux kernel version?  Perhaps there is a device driver bug
on your Lenny machine, which has since been fixed on your Kurumin machine?
 If the kernel really is getting stuck in an I/O loop (which sounds to be
the case, if ^z doesn't suspend the proecess), then an strace would be
informative.  Have you tried a different block size (dd bs=1024, for
example)?

> 
> I really thank you for your attention.
> 
- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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