Bristol Digest, Vol 615, Issue 4

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Today's Topics:

1. Re: dd dev to dev multipartition and more... (Alex Butcher)
2. Re: dd dev to dev multipartition and more... (phil)
3. Nova T 500 no detection (Peter Hemmings)


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

Message: 1
Date: Fri, 28 Aug 2015 15:48:47 +0100 (BST)
From: Alex Butcher <lug@assursys.co.uk>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Cc: rwatollenaar@gmail.com
Subject: Re: [bristol] dd dev to dev multipartition and more...
Message-ID:
<alpine.LRH.2.11.1508281548160.1250@zlgugi.of5.nffheflf.cev>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed

And make sure neither has any mounted filesystems when you do it.

Best Regards,
Alex

On Fri, 28 Aug 2015, Amias Channer wrote:

>
> Hello RT,
>
> Your second DD command is indeed overwriting the first partition with the
> second one. You might do better to run on DD command that does the whole
> disk not the just a partition.
>
> E.g. dd if=/dev/sdx of=/dev/sdy
>
> Cheers
> Amias
>
> On 27 Aug 2015 16:42, "RT" <rwatollenaar@gmail.com> wrote:
> Hi All and Anyone,
>
> been a while since I called upon some help here.....
>
> I have two sd cards one big one with Raspbian and another
> smaller one that is clean.
>
> I want to get the image of the first onto the latter and someone
> on internet suggests pluggin both in to a linux machine and
> dd-ing across
>
> dd if=/dev/sdxx of=/dev/sdyy
>
> The actual useful part of the image is much smaller than the
> size of the clean sd card and the claim is that losing the
> garbage should not hurt.
>
> dd would execute the above through some errors but it should
> work.
>
> 1-dd executes but gives no error
>
> 2-I have two partitions on the source sd card which I copied
> across
>
> dd if=/dev/sdx1 of=/dev/sdy1
> dd if=/dev/sdx2 of=/dev/sdy1
>
> which may be me overwriting the work of the first dd with the
> efforts of the second dd.
>
> In any event the result of all this cookery does not boot my
> raspberry Pi.
>
> Can anyone advise how best to get the larger image onto a
> smaller card, preferably without the use of things like GParted
> or other tools not available on a very basic linux distribution.
>
> Thanks.
>
> Roland.
>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
>
>



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

Message: 2
Date: Fri, 28 Aug 2015 17:30:02 +0100
From: phil <philssmith@btinternet.com>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Cc: rwatollenaar@gmail.com
Subject: Re: [bristol] dd dev to dev multipartition and more...
Message-ID: <55E08C8A.9030703@btinternet.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

Hi

You can't just dd from the larger partition to a smaller one
because you cannot guarantee that all the data is contiguous from the
start of the partition. The copy may work, it may not. Read the first
answer to this question: it explains this better than I could.
http://askubuntu.com/questions/409204/how-to-clone-to-a-smaller-harddisk

Using dd to copy the entire disk will suffer from the same issue.

(The following procedure includes the risk of trashing the original data
so backup first if possible):

1) Use resize2fs to reduce size of source filesystem down to size of the
destination partition (or a bit lower if possible to provide some headroom).
2) Use fdisk to reduce the size of the source partition to the size of
the destination partition
3) Run dd to copy the partition to the destination partition both of
which are now the same size

After all the above it may seem safer, easier and quicker to create a
new partition on the new sd card, format it and copy the files across
using rsync or similar. And you will be right - this method is all these
things. Why are you restricted to using dd?

PS. It is usually better to provide a link rather than state: "and
someone on internet suggests" This helps check the veracity of the
statement and also to correct it if the information is incorrect. (which
seems to be the case here because dd cannot tell what is and what is not
garbage data).


Cheers
Phil Smith


On 28/08/15 15:48, Alex Butcher wrote:
> And make sure neither has any mounted filesystems when you do it.
>
> Best Regards,
> Alex
>
> On Fri, 28 Aug 2015, Amias Channer wrote:
>
>>
>> Hello RT,
>>
>> Your second DD command is indeed overwriting the first partition with
>> the
>> second one. You might do better to run on DD command that does the whole
>> disk not the just a partition.
>>
>> E.g. dd if=/dev/sdx of=/dev/sdy
>>
>> Cheers
>> Amias
>>
>> On 27 Aug 2015 16:42, "RT" <rwatollenaar@gmail.com> wrote:
>> Hi All and Anyone,
>>
>> been a while since I called upon some help here.....
>>
>> I have two sd cards one big one with Raspbian and another
>> smaller one that is clean.
>>
>> I want to get the image of the first onto the latter and someone
>> on internet suggests pluggin both in to a linux machine and
>> dd-ing across
>>
>> dd if=/dev/sdxx of=/dev/sdyy
>>
>> The actual useful part of the image is much smaller than the
>> size of the clean sd card and the claim is that losing the
>> garbage should not hurt.
>>
>> dd would execute the above through some errors but it should
>> work.
>>
>> 1-dd executes but gives no error
>>
>> 2-I have two partitions on the source sd card which I copied
>> across
>>
>> dd if=/dev/sdx1 of=/dev/sdy1
>> dd if=/dev/sdx2 of=/dev/sdy1
>>
>> which may be me overwriting the work of the first dd with the
>> efforts of the second dd.
>>
>> In any event the result of all this cookery does not boot my
>> raspberry Pi.
>>
>> Can anyone advise how best to get the larger image onto a
>> smaller card, preferably without the use of things like GParted
>> or other tools not available on a very basic linux distribution.
>>
>> Thanks.
>>
>> Roland.
>>
>>
>> _______________________________________________
>> Bristol mailing list
>> Bristol@mailman.lug.org.uk
>> https://mailman.lug.org.uk/mailman/listinfo/bristol
>>
>>
>>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol




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

Message: 3
Date: Fri, 28 Aug 2015 23:53:53 +0100
From: Peter Hemmings <peter@hemmings.eclipse.co.uk>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: [bristol] Nova T 500 no detection
Message-ID: <55E0E681.10602@hemmings.eclipse.co.uk>
Content-Type: text/plain; charset=utf-8; format=flowed

Hi,

I just tried to use Kaffeine and dont seem to have a card!

dmesg | grep -i dvb shows nothing.

As it always worked OK.

Could someone confirm the order, does the board get detected then
modules load!?

I did try older kernels for fedora 22 but still the same lack of
detection.

Any other ideas as to what has happened and why?


Will give the H/W some wiggling tomorrow but dont think that is the problem.

Regards

--
Peter H



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

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