Re: Problem with dd 5.97 (Ubuntu 7)

[Jim Meyering]

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.