Re: Problem with dd 5.97 (Ubuntu 7)

[Ernie Limperis]

Heh.  I've never used strace, but after trying it out the thought of
running it on a 60GB dd transfer gives me The Fear...I can't tell whether
there's a way to have it display only syscall failures.  I will install
the latest coreutils, though.


Jim Meyering wrote:
> Ernie Limperis <address@hidden> wrote:
>
> > I had a strange problem with an apparent silent failure of dd to clone a 
> > Windows-partitioned
> > disk yesterday.
> >
> > Environment:  Ubuntu Linux, kernel 2.6.20-16-generic #2 SMP
> >              AMD Athlon(tm) 64 X2 Dual Core Processor 3800+
> >              1G ram
> >              dd version 5.97
> >
> > Disks:  Source: Seagate 60GB, about five years old, /dev/hdc
> >        Target: Western Digital 80GB, new OEM., /dev/hdd
> >        both IDE on a VIA controller (Asus M2V-TVM motherboard,
> >            chipset = K8M890/VT8327R Plus)
> >
> > Source Partition Table:  something like this
> >
> >   /dev/hdc1 *  1        1530          SFS
> >   /dev/hdc2    1530    <end of disk>  Win95 LBA
> >   /dev/hdc5    #
> >   /dev/hdc6    #  all Extended partitions, type SFS
> >   /dev/hdc7    #  roughly equal sized at 10GB
> >   /dev/hdc8    #
> >
> >
> > Command:  dd if=/dev/hdc of=/dev/hdd conv=notrunc,noerror bs=32768  # also 
> > occured with bs=4096
> >
> > Behavior:  On multiple attempts, dd copied as far as hdc6 then exited with no
> > error, reporting the full 60GB copy.   fdisk on the target showed hdd7 as 
> > taking up the rest of
> > the disk with an "empty" device type. Read errors appeared at roughly 30 GB 
> > because of
> > bad sectors on the source, but the copy process continued as documented.  
> > Partition-by-partition
> > dd worked fine (except for the read errors on one partition).
>
>
> Thanks for the report.
>
> If you can reproduce it while running via strace,
> and the strace output shows that there is a syscall
> failure, yet dd still doesn't report any problem,
> then *that* would be a bug:
>
> strace -o /tmp/strace dd if=/dev/hdc of=/dev/hdd conv=notrunc,noerror bs=32768
>
> Even if you find a problem that way, I suggest you get a newer
> version of dd and retry with that one.  The latest stable release
> is coreutils-6.9.


--
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Ernie Limperis                    510-525-8801
address@hidden              cell 510-682-6373
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