9:51 a.m.
If you want to copy something big from one partition to another the
old dd method is for you. You have to do it right. This means that:
1. The destination partition MUST be at least a byte larger than the
source partition where the data is coming from. This is essential!
2. The dd copies everything including the file system.
3. Be ready to check the file system of the copy with fsck.
4. If you are making a copy of an entire working Fedora system make sure
you change all the entries in /etc/grub.conf and /etc/fstab files to the
new partitions of the copy before you try to run it.
5. To copy a partition from the source, called /dev/source to a
destination partition called /dev/destination use the standard dd form:
# dd if=/dev/source of=/dev/destination
6. Always run dd in the source computer.
7. Take your time doing all this. It will save you problems later. There
are a lot of ways to make errors.
8. Think of how dd works this way, dd see's the source partition as just
a pile of bytes. It takes a few bytes each cycle and puts those bytes on
the destination partition. When done dd reports how many bytes it found
and how many it put on destination. They are the same large number.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
10:18 a.m.
On Fri, 2007-08-31 at 08:51 -0600, Karl Larsen wrote:
If you want to copy something big from one partition to another
the
old dd method is for you. You have to do it right. This means that:
1. The destination partition MUST be at least a byte larger than the
source partition where the data is coming from. This is essential!
2. The dd copies everything including the file system.
3. Be ready to check the file system of the copy with fsck.
4. If you are making a copy of an entire working Fedora system make sure
you change all the entries in /etc/grub.conf and /etc/fstab files to the
new partitions of the copy before you try to run it.
5. To copy a partition from the source, called /dev/source to a
destination partition called /dev/destination use the standard dd form:
# dd if=/dev/source of=/dev/destination
6. Always run dd in the source computer.
7. Take your time doing all this. It will save you problems later. There
are a lot of ways to make errors.
8. Think of how dd works this way, dd see's the source partition as just
a pile of bytes. It takes a few bytes each cycle and puts those bytes on
the destination partition. When done dd reports how many bytes it found
and how many it put on destination. They are the same large number.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
I'm certain there will be several posts explaining the errors in
this document, so I won't put in any effort into things in that
respect.
Being a parent and grandparent, I've learnt that it's, um... well,
"counter-productive" to be at all times critical or negative or
nit-picky or, well, you get the picture. So let me just say that the
benign intention here is well recognised and much appreciated.
You're a pain, Karl, and you simply don't listen to anybody if you're busy
doing your own thing. And that is so VERY frustrating. But it's impressive
how tenacious you can be, and it's impressive that a man of your age
is so eager and capable of discovery in things which are generally thought
to be the bailiwick of the youngish, pedigreed nerd.
And it's very appreciated when somebody who has solved a problem or
discovered a new trick or in any way "built a better mousetrap" in our
Little Linux World (tm) shares it with the community at large. Kudos.
However, and this is not addressed at you specifically, Karl, but is
more a pained wail to the ether, it's just clicked for me (and I mean
audible click), that a scary percentage of "help" out there is just
like this one.
I've just flashed on all the problems I've had in the past, obscure
or just burdened with pressures of time, where I've desperately looked
for solutions, been overjoyed at finding something like the above, and
then discovering that it's all bunk. Good heavens! No wonder people
out there get their knickers all twisted about Linux. If 3 out of 8
solutions they find for any given problem are horse pucky, why WOULDN'T
they be upset?
Two brief points, and then I'm off to the weekend.
1. Karl, if you read all the posts in all the (many) threads you started
regarding your little "new hard drive" adventure, really read and understood
them, you'd discover how inaccurate what you've written above indeed is.
2. The above is now out there in the public domain, and someday, somebody
is going to find it and think,
"Excellent! I've been wondering how to do this!". And then they're
going
to have a bad day.
Have a nice weekend everybody.
Andy
9:21 a.m.
Andrew Kelly wrote:
On Fri, 2007-08-31 at 08:51 -0600, Karl Larsen wrote:
> If you want to copy something big from one partition to another the
>
>
I'm certain there will be several posts explaining the errors in
this document, so I won't put in any effort into things in that
respect.
Well let me help Andy. First it is not a document! It is an email on
the Fedora List. Yes there are no errors in that email because it was
written on the new hard drive which was a copy of this f7. The copy was
a complete success.
Second, I learned a lot of stuff from people on this list. And I
wrote another email which I put here for your interest.
If you want to copy something big from one partition to another the
old dd method is for you. You have to do it right. This means that:
1. The destination partition MUST be as large or larger than the source
partition where the data is coming from. This is essential!
2. The dd copies everything including the file system.
3. Be ready to check the file system of the copy with fsck.
4. If you are making a copy of an entire working Fedora system make sure
you change all the entries in /etc/grub.conf and /etc/fstab files to the
new partitions of the copy before you try to run it.
5. To copy a partition from the source, called /dev/source to a
destination partition called /dev/destination use the standard dd form:
# dd if=/dev/source of=/dev/destination
6. Make certain that all Hard Drives are registered in bios. Put the F7
Rescue CD in, or your F7 DVD in, and select Rescue. When it asks if you
want to mount your fedora system do not just go to the Prompt. At the
prompt do your dd transfer.
7. Take your time doing all this. It will save you problems later. There
are a lot of ways to make errors.
8. Think of how dd works this way, dd see's the source partition as just
a pile of bytes. It takes a few bytes each cycle and puts those bytes on
the destination partition. When done dd reports how many bytes it found
and how many it put on destination. They are the same large number.
9. The default number of bytes per Block is defaulted to 150. The info
DD says this:
`bs=BYTES'
Set both input and output block sizes to BYTES. This makes `dd'
read and write BYTES per block, overriding any `ibs' and `obs'
settings.
So if in a hurry you can use bs=15000 which will be a good thing because
the IDE hard drive controllers are quite slow. So rather than sending
just 150 bytes per change, you send 15,000. A transfer will look like:
# dd bs=15000 if=/dev/sda6 of=/dev/sdb5
I have not tried this. No reason to think it will not work.
So Andy please read this latest email and see if it is correct.
Again I have done everything except the 9. as I say so it works.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
10:20 a.m.
Karl Larsen wrote:
Well let me help Andy. First it is not a document! It is an email
on
the Fedora List. Yes there are no errors in that email because it was
written on the new hard drive which was a copy of this f7. The copy was
a complete success.
If you've searched for answers before you should have realised by now
that most of the top links in most technical searches are from mailing
list archives. But I suppose you've never done that before.
9. The default number of bytes per Block is defaulted to 150. The
info
Where exactly did you learn that the default is 150? It's wrong. You've
been told this before and instructed to Google for the correct
information, but you have just ignored it and chosen to believe whatever
pathetic excuse for a how-to that you read in some godforsaken part of
the web, thereby proving your thinkheadedness.
The default is 512 bytes. [1]
[1] http://www.opengroup.org/onlinepubs/009695399/utilities/dd.html
--
Regards,
विवेक ज. पाटणकर (Vivek J. Patankar)
Registered Linux User #374218
Fedora release 7 (Moonshine)
Linux 2.6.22.4-65.fc7 x86_64
10:38 a.m.
Vivek J. Patankar wrote:
Karl Larsen wrote:
> Well let me help Andy. First it is not a document! It is an email
> on the Fedora List. Yes there are no errors in that email because it
> was written on the new hard drive which was a copy of this f7. The
> copy was a complete success.
If you've searched for answers before you should have realised by now
that most of the top links in most technical searches are from mailing
list archives. But I suppose you've never done that before.
> 9. The default number of bytes per Block is defaulted to 150. The info
Where exactly did you learn that the default is 150? It's wrong.
You've been told this before and instructed to Google for the correct
information, but you have just ignored it and chosen to believe
whatever pathetic excuse for a how-to that you read in some
godforsaken part of the web, thereby proving your thinkheadedness.
The default is 512 bytes. [1]
[1] http://www.opengroup.org/onlinepubs/009695399/utilities/dd.html
My reading of the man page was wrong but it changes nothing. The
default number error is not going to stop the person using it from
succeeding. So the email is good to go.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
3:45 p.m.
On Mon, 2007-09-03 at 09:38 -0600, Karl Larsen wrote:
Vivek J. Patankar wrote:
> Karl Larsen wrote:
>> Well let me help Andy. First it is not a document! It is an email
>> on the Fedora List. Yes there are no errors in that email because it
>> was written on the new hard drive which was a copy of this f7. The
>> copy was a complete success.
>
> If you've searched for answers before you should have realised by now
> that most of the top links in most technical searches are from mailing
> list archives. But I suppose you've never done that before.
>
>
>> 9. The default number of bytes per Block is defaulted to 150. The info
>
> Where exactly did you learn that the default is 150? It's wrong.
> You've been told this before and instructed to Google for the correct
> information, but you have just ignored it and chosen to believe
> whatever pathetic excuse for a how-to that you read in some
> godforsaken part of the web, thereby proving your thinkheadedness.
>
> The default is 512 bytes. [1]
>
> [1] http://www.opengroup.org/onlinepubs/009695399/utilities/dd.html
>
>
My reading of the man page was wrong but it changes nothing. The
default number error is not going to stop the person using it from
succeeding. So the email is good to go.
Karl, if it doesn't matter and it's wrong, fix it or leave it out
altogether. You'll gain the respect of your interlocutors here and the
awe of newbies reading your instructions if you don't include gratuitous
false information.
If it *does* matter, make sure it's correct and have an authoritative
source to back you up. That's the best way to shut your critics up.
If it does matter and you can't find an authoritative source, ask your
question here first. Then you'll have the answer, people who can answer
you will do so without being harsh, and the jackasses on the list won't
have you as an excuse to bray.
--
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs
12:58 p.m.
Matthew Saltzman wrote:
On Mon, 2007-09-03 at 09:38 -0600, Karl Larsen wrote:
> Vivek J. Patankar wrote:
>
>> Karl Larsen wrote:
>>
>>> Well let me help Andy. First it is not a document! It is an email
>>> on the Fedora List.
If you want to copy something big from one
partition to another the old dd method is for you. You have to do it right. This means
that:
1. The destination partition MUST be as large or larger than the source partition where
the data is coming from. This is essential!
2. The dd copies everything including the file system.
3. Be ready to check the file system of the copy with fsck.
4. If you are making a copy of an entire working Fedora system make sure you change all
the entries in /etc/grub.conf and /etc/fstab files to the new partitions of the copy
before you try to run it.
5. To copy a partition from the source, called /dev/source to a destination partition
called /dev/destination use the standard dd form:
# dd if=/dev/source of=/dev/destination
6. Make certain that all Hard Drives are registered in bios. Put the F7 Rescue CD in, or
your F7 DVD in, and select Rescue. When it asks if you want to mount your fedora system do
not just go to the Prompt. At the prompt do your dd transfer.
7. Take your time doing all this. It will save you problems later. There are a lot of ways
to make errors.
8. Think of how dd works this way, dd see's the source partition as just a lot of
bytes. It takes a few bytes each cycle and puts those bytes on the destination partition.
When done dd reports how many bytes it found and how many it put on destination. They are
the same large number.
9. The default number of bytes per Block is defaulted to 512. The info DD says this:
`bs=BYTES'
Set both input and output block sizes to BYTES. This makes `dd'
read and write BYTES per block, overriding any `ibs' and `obs'
settings.
So if in a hurry you can use bs=15000 which will be a good thing because the IDE hard
drive controllers are quite slow. So rather than sending just 512 bytes per change, you
send 15,000. A transfer will look like:
# dd bs=15000 if=/dev/sda6 of=/dev/sdb5
I have not tried this. No reason to think it will not work.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
11:06 a.m.
Karl,
For the sake of new users who are routinely instructed to research the
list archives prior to asking a question, please explain the following
points:
Karl Larsen wrote:
1. The destination partition MUST be at least a byte larger than the
source partition where the data is coming from. This is essential!
Why must the
destination partition be larger than the source partition?
It is my understanding that the ideal situation is for both partitions
to be the same size.
4. If you are making a copy of an entire working Fedora system make
sure you change all the entries in /etc/grub.conf and /etc/fstab files
to the new partitions of the copy before you try to run it.
This needs to be
elaborated upon. Both "grub.conf" and "fstab" are
critical files that may cause severe problems if misconfigured. Since
this is a new thread, you must assume a reader is unaware of the changes
you are referencing.
6. Always run dd in the source computer.
Is it really wise to
copy a mounted partition with a live file system?
What if the file system is being written to during the copy? The advice
to use a live CD (given in one of the other myriad threads on this
topic) seems more prudent.
Thank you,
Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer
1:44 p.m.
Matthew J. Roth wrote:
Karl,
For the sake of new users who are routinely instructed to research the
list archives prior to asking a question, please explain the following
points:
Karl Larsen wrote:
> 1. The destination partition MUST be at least a byte larger than the
> source partition where the data is coming from. This is essential!
Why must the destination partition be larger than the source
partition? It is my understanding that the ideal situation is for
both partitions to be the same size.
It is hard to be sure of partition size. I
was using two Hard Drives
with exactly the same number of total cylinders to make the same 160 GB.
I made the destination partition 7 cylinders larger than the source with
fdisk. That is a lot of bytes bigger. But yes identical is better if you
know how to do that :-)
> 4. If you are making a copy of an entire working Fedora system
make
> sure you change all the entries in /etc/grub.conf and /etc/fstab
> files to the new partitions of the copy before you try to run it.
This needs to be elaborated upon. Both "grub.conf" and "fstab" are
critical files that may cause severe problems if misconfigured. Since
this is a new thread, you must assume a reader is unaware of the
changes you are referencing.
It is beyond the scope of this short paper.
> 6. Always run dd in the source computer.
Is it really wise to copy a mounted partition with a live file
system? What if the file system is being written to during the copy?
The advice to use a live CD (given in one of the other myriad threads
on this topic) seems more prudent.
It didn't seem to make any problem. I
was getting emails and sending
them. They were all working normal on this computer and the destination
copy runs just great.
Thank you,
Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
3:50 p.m.
It didn't seem to make any problem. I was getting emails and
sending
them. They were all working normal on this computer and the destination
copy runs just great.
Karl F. Larsen, AKA K5DI
Karl, the danger is not with the source so much as
it is with the
destination (i.e. copy). At source dd is just reading. Any changes
happening at source are happening through normal operating system
behaviour. To the source dd is simply another process running,
reading data off its drive. The issue is at destination. Granted the
important files (system binaries, config files) likely will not change
while simply surfing the net and checking emails. What will change
are temporary Internet files, browser config files if you happen to
save a password or respond to some other such browser popup, email
INBOX and other such files if you are using a POP email client, and
other such potential changes. So yes, the system will likely appear
to run fine as the important system files will likely have been copied
over properly given they will not have changed during the process.
But allocated space and free space pointers will change throughout
therefore corrupting the file system. That will eventually manifest
itself in problems that may appear to make no sense. And of course
numerous files will have been created and/or deleted during the
process causing potential problems (think photocopying of book
analogy).
The other caveat you do not mention is that this would not necessarily
work well if you were putting the copy into a different system
(different hardware - different drivers required, different
configuration required).
The read between the lines point made by Matthew as I saw it is that
you cannot simply put together a "do this, this and this because I
said so" tutorial for such a potentially destructive process which
requires certain required knowledge to be able to do properly given
you brief instructions. Not to mention your advice is flawed in many
ways as has already been pointed out.
I'm hanging up my keyboard on this topic after this post. Far too
many experienced/knowledgeable people have put far too much effort
trying to explain something to you that you consistently choose to
ignore. Nobody is asking you to get up and say "I am wrong." It's
not a matter of wrong or right. It's a matter of saying, "I learned
something I didn't know. Now I know better." Nobody is asking you to
abandon your convictions. Just don't be so stubborn in them when it
is clear that they are misplaced.
Jacques B.
5:03 p.m.
Jacques B. wrote:
> It didn't seem to make any problem. I was getting emails
and sending
> them. They were all working normal on this computer and the destination
> copy runs just great.
>
> Karl F. Larsen, AKA K5DI
>
Karl, the danger is not with the source so much as it is with the
destination (i.e. copy). At source dd is just reading. Any changes
happening at source are happening through normal operating system
behaviour. To the source dd is simply another process running,
reading data off its drive. The issue is at destination. Granted the
important files (system binaries, config files) likely will not change
while simply surfing the net and checking emails. What will change
are temporary Internet files, browser config files if you happen to
save a password or respond to some other such browser popup, email
INBOX and other such files if you are using a POP email client, and
other such potential changes. So yes, the system will likely appear
to run fine as the important system files will likely have been copied
over properly given they will not have changed during the process.
But allocated space and free space pointers will change throughout
therefore corrupting the file system. That will eventually manifest
itself in problems that may appear to make no sense. And of course
numerous files will have been created and/or deleted during the
process causing potential problems (think photocopying of book
analogy).
The other caveat you do not mention is that this would not necessarily
work well if you were putting the copy into a different system
(different hardware - different drivers required, different
configuration required).
The read between the lines point made by Matthew as I saw it is that
you cannot simply put together a "do this, this and this because I
said so" tutorial for such a potentially destructive process which
requires certain required knowledge to be able to do properly given
you brief instructions. Not to mention your advice is flawed in many
ways as has already been pointed out.
I'm hanging up my keyboard on this topic after this post. Far too
many experienced/knowledgeable people have put far too much effort
trying to explain something to you that you consistently choose to
ignore. Nobody is asking you to get up and say "I am wrong." It's
not a matter of wrong or right. It's a matter of saying, "I learned
something I didn't know. Now I know better." Nobody is asking you to
abandon your convictions. Just don't be so stubborn in them when it
is clear that they are misplaced.
Jacques B.
I will not expect you to use those rules. I wrote them for myself
and thought others might be interested. I have shown I know what is
perfect. I didn't do it in a perfect way. But the copy booted up and
works fine. So most of the copy is good.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
11:22 a.m.
Karl Larsen wrote:
If you want to copy something big from one partition to another the
old dd method is for you. You have to do it right. This means that:
1. The destination partition MUST be at least a byte larger than the
source partition where the data is coming from. This is essential!
It must be at least exactly the same size. Why should it be a byte
larger?
6. Always run dd in the source computer.
I'm not sure what other computer you'd run it on. Do you
mean over a network? Or possibly you mean the system you
have mounted as /, in which case see 9.
9. When using dd to clone a partition have both the source and
destinations unomunted or at least mounted read only.
--
imalone
6077
days inactive
6081
days old
11 comments
7 participants
participants (7)
-
Andrew Kelly -
Ian Malone -
Jacques B. -
Karl Larsen -
Matthew J. Roth -
Matthew Saltzman -
Vivek J. Patankar