NFS problem

John Clark jclark at
Wed May 2 17:42:43 UTC 2007

Chuck Swiger schrieb:
> John Clark wrote:
>> I am copying a 'disk image' to an NFS mounted volume.
>> I'm using:
>> dd if=/dev/ad0 of=Disk.img
>> After dd completes the number of blocks indicated is what the raw 
>> disk device should be. However, when I look at the NFS mounted image, 
>> the file size is anything but the 80 GB size it should be.
> How big is it?  Is the data complete/intact up to the point when it 
> stopped?

What I'm doing is cloning a disk, and making it network accessible. So 
it is an 80 GB disk image.

When I mount the 'results', fsck, does start to pick up problems,  and 
on one of the partitions, basically resulted
in a slew of corrupted inodes.

So my suspicion is that there are missing blocks scattered throughout.

 >Can you create enough local space on a second drive (or do this by 
individial partitions instead) to create the image locally, and then 
copy the file at once via NFS?  >It'd be nice to see whether that worked 

I'll see if I can set this up... but that would only verify that dd 
wasn't doing something strange...

One trick I tried was to use 'tee' to create the NFS image, and then 
continue the pipe with a 'cksum':

dd if=/dev/ad0 |  tee Disk.img | cksum

Tee stopped at some point, probably about 2.5 GB with a 'file too 
large'... the CVS sources that I'm using
are pretty recent, as in within the last month...

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