[TriLUG] mount -o loop on a gzipped image?
jbebel at ncsu.edu
Wed Oct 5 15:12:16 EDT 2005
You can't just put a gzipped filesystem on a loopback device. The
loopback device isn't capable of handling gzipping. It seems like
something that could be possible at least for a read only filesystem,
but for something read/write, managing that within a gzipped file would
be difficult. In any case, there's no way to do that quite yet with the
normal losetup tool.
As for mounting partitions within a loopback filesystem, I don't think
that's particularly easy either. What comes to mind is to extract the
partition table, analyze it for the blocks for each partition, then
extract that partition into a separate file with dd. Alternatively, you
might be able to use the --offset option to losetup, though I've never
A google search turns up a discussion of something like this here:
Brian Henning wrote:
> Hi Y'all,
> I've created a compressed image of a drive using g4u. The drive is
> 70GB; the image is about 10GB (lots of empty space). My question is
> 1) Is it possible to somehow filter mount through gzip so that I can do
> a loopback mount on a zipped image without needing to unzip the image?
> I do not have 70GB free in which to unzip.
> 2) If the image contains multiple partitions, can I do #1 and also
> choose a particular partition to mount within the image?
> I want to do this just as sanity-checking to make sure g4u did the Right
> Thing. Because this is $boss's wife's laptop being sent for service,
> and losing all the data would probably take my job along with it.
> I'm looking through manpages and googling also, but I thought I would
> pose the question to the list as well.
> Thank all!
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