1 Topic by BT

  • BT
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Topic: Copying an unknown partition

Since I've started dipping my toes into Linux lately, when Partition Magic refused to copy an unknown partition type (happened to be a TrueCrypt partition) I tried the gparted that ships with Ubuntu 7.04 (people here keep suggesting that they used some really old, buggy version of gparted:  is this true, and if so why on earth did they?).

But that too refused to allow the copy operation.  I can understand why a partition manager needs to be familiar with the associated file system (or other internal structure) if it's resizing a partition, and why it might like to understand these internals during a copy operation in order to copy no more than it actually needs to, but to refuse outright to copy a partition of unknown internal format (rather than just copy every byte) seems a bit unreasonable.

I suppose I could work around the problem by using a TrueCrypt container file within a dedicated partition, but the addition of an extra level of otherwise unnecessary mapping seems silly.  Am I just missing some means by which gparted would perform the copy, or some reason why it really can't?

Thanks.

2 Reply by class413

  • class413
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Re: Copying an unknown partition

Gparted does various partition operations, like creating a partition, shrinking, exparding, formatting etc. It doesn't support each partition type (each filesystem) on the same degree, for various reasons. Each type of operation on each filesystem is performed by specific tools or commands.
http://gparted.sourceforge.net/features.php

It isn't just a copy tool, it is mainly intended to modify partitions. You could try to use another specific tool, clonezilla. You can find it to the main GParted site, as a liveCD together with Gparted 0.3.4-7.

http://gparted.sourceforge.net/news.php
http://gparted.free.fr/GParted-Clonezil … ezilla.txt

http://gparted.sf.net/

I can't promess anything, but I know it is more efficient to copy partitions than Gparted.  Try it please, and tell us the result!

*** It is highly recommended to backup any important files before doing resize/move operations. ***

3 Reply by BT

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Re: Copying an unknown partition

Haven't tried clonezilla yet, since its documentation also talks about 'supported file systems' (at least suggesting that it too will haughtily refuse to deal with others) - but I noticed that it (like gparted) apparently uses dd under the covers to do the real work.  Haven't tried dd yet either, pending answers to a couple of questions about the alignment behavior of its block-size parameters (one source seems to state that when the block size is multiple sectors any partial block at the end of a copy operation is left uncopied).  I did try a little (runs from two floppies) NetBSD utility called g4u that seemed to do the job (i.e., perform a dumb bit-for-bit copy of a TrueCrypt partition, though I haven't yet tried doing so to a different offset on the target disk from the source disk offset) and performed at close to the theoretical bandwidth of the drives (41+ MB/sec on the innermost cylinders of the 160 GB source and destination drives).