Thanks Guus.
[Guus wrote: Also, is there anything in the kernel messages (dmesg)
that gives a clue?]
This is looking like a hard drive (most likely), ata controller, or
ata driver issue as:
dd if=a4b4.tar skip=123166576 of=/dev/null
dd: reading `a4b4.tar': Input/output error
0+0 records in
0+0 records out
0 bytes (0 B) copied, 13.7423 s, 0.0 kB/s
produces the following dmesg output:
--< start clip >--
ata3.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:00:88:fe:28/00:00:23:00:00/40 tag 0 ncq 4096 in
res 41/40:00:8f:fe:28/54:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
ata3.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:00:88:fe:28/00:00:23:00:00/40 tag 0 ncq 4096 in
res 41/40:00:8f:fe:28/06:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
ata3.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:00:88:fe:28/00:00:23:00:00/40 tag 0 ncq 4096 in
res 41/40:00:8f:fe:28/06:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
ata3.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:00:88:fe:28/00:00:23:00:00/40 tag 0 ncq 4096 in
res 41/40:00:8f:fe:28/06:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
ata3.00: exception Emask 0x0 SAct 0x3 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:00:88:fe:28/00:00:23:00:00/40 tag 0 ncq 4096 in
res 41/40:00:8f:fe:28/06:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
ata3.00: exception Emask 0x0 SAct 0x2 SErr 0x0 action 0x0
ata3.00: irq_stat 0x40000008
ata3.00: cmd 60/08:08:88:fe:28/00:00:23:00:00/40 tag 1 ncq 4096 in
res 41/40:00:8f:fe:28/06:00:23:00:00/40 Emask 0x409 (media error) <F>
ata3.00: status: { DRDY ERR }
ata3.00: error: { UNC }
ata3.00: configured for UDMA/133
sd 2:0:0:0: [sda] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
sd 2:0:0:0: [sda] Sense Key : Medium Error [current] [descriptor]
Descriptor sense data with sense descriptors (in hex):
72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00
23 28 fe 8f
sd 2:0:0:0: [sda] Add. Sense: Unrecovered read error - auto reallocate failed
end_request: I/O error, dev sda, sector 589889167
ata3: EH complete
sd 2:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB)
sd 2:0:0:0: [sda] Write Protect is off
sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
--< end clip >--
On Tue, Sep 8, 2009 at 3:10 PM, Guus Snijders<gsnijders@xxxxxxxxx> wrote:
> Something else you could try is using ddrescue on the file; whereas
> "dd" stops when it encounters an error, ddrescue
> will keep trying to read as much as possible.
> It feels a bit like the disk (on which the image is stored) is giving
> a read error, causing dd to stop.
Thanks, I'm trying ddrescue on it right now.
