When will ddrescue return to warp speed?

[James Watts]

Hello,

I am currently rescuing a 500GB drive. When I first started ddrescue, the routine began recovering data at the blistering rate of 18-20 MB/s. Then it encountered an error (after recovering about 20GB) and the drive got hung-up and did not respond to commands. So I had to turn off the drive, turn it on again, and restart ddrescue. Now, it's been going for two days holding at a rate of 300-500 KB/s. It has not encountered any more errors according to the on-screen info and the log (see below). So why will it not ramp up to the high-speed from before? At this rate, it could take weeks to complete.

Thoughts? Am I doing something wrong? What would you do differently?

Thank you,

James


wattage@tektite:~$ sudo ddrescue /dev/sdb1 "/media/Expansion Drive/hm.img" "/media/Expansion Drive/hm.log"
[sudo] password for wattage:


Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued:    26851 MB,  errsize:    128 kB,  errors:       1
Current status
rescued:    56575 MB,  errsize:    128 kB,  current rate:     327 kB/s
   ipos:    56575 MB,   errors:       1,    average rate:     353 kB/s
   opos:    56575 MB,     time from last successful read:       0 s
Copying non-tried blocks...
Interrupted by user


# Rescue Logfile. Created by GNU ddrescue version 1.11
# current_pos  current_status
0xD2C290600     ?
#      pos        size  status
0x00000000  0x640791000  +
0x640791000  0x00000200  -
0x640791200  0x0001F200  *
0x6407B0400  0x6EBAE0200  +
0xD2C290600  0x6510238000  ?

_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue

[Antonio Diaz Diaz-2]

James Watts wrote:
> I am currently rescuing a 500GB drive. When I first started ddrescue, the
> routine began recovering data at the blistering rate of 18-20 MB/s. Then it
> encountered an error (after recovering about 20GB) and the drive got hung-up
> and did not respond to commands. So I had to turn off the drive, turn it on
> again, and restart ddrescue. Now, it's been going for two days holding at a
> rate of 300-500 KB/s. It has not encountered any more errors according to
> the on-screen info and the log (see below). So why will it not ramp up to
> the high-speed from before? At this rate, it could take weeks to complete.

Did you only reset the drive (/dev/sdb) instead of rebooting the whole
computer? Maybe the controller or even the kernel switched to a slower
mode after the error.


> Thoughts? Am I doing something wrong? What would you do differently?

If the reboot doesn't work, I would try to stop ddrescue and restart it
at the next multiple of 64KiB. (The next position with four trailing
zeros: 0xD2C290600 ==> 0xD2C2A0000).


Regards,
Antonio.


_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue

[James Watts]

Hi Antonio. Thanks for the reply. I tried both of your suggestions. No change in results. It still refuses to exceed 300-500 KB/s.

I shut down and powered off the computer and both drives multiple times. I restarted ddrescue multiple times.

Any other thoughts? I just don't understand why it would initially recover so quickly and now it just refuses...

Thank you,

James

On Wed, Jul 15, 2009 at 12:26 PM, Antonio Diaz Diaz <antonio_diaz@...> wrote:

James Watts wrote:

I am currently rescuing a 500GB drive. When I first started ddrescue, the
routine began recovering data at the blistering rate of 18-20 MB/s. Then it
encountered an error (after recovering about 20GB) and the drive got hung-up
and did not respond to commands. So I had to turn off the drive, turn it on
again, and restart ddrescue. Now, it's been going for two days holding at a
rate of 300-500 KB/s. It has not encountered any more errors according to
the on-screen info and the log (see below). So why will it not ramp up to
the high-speed from before? At this rate, it could take weeks to complete.

Did you only reset the drive (/dev/sdb) instead of rebooting the whole computer? Maybe the controller or even the kernel switched to a slower mode after the error.

Thoughts? Am I doing something wrong? What would you do differently?

If the reboot doesn't work, I would try to stop ddrescue and restart it at the next multiple of 64KiB. (The next position with four trailing zeros: 0xD2C290600 ==> 0xD2C2A0000).


Regards,
Antonio.

_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue

[andrew zajac-2]

Maybe you are dealing with physical damage to the drive?  If one of the head's amplification system if damaged, the head will use error correction to get a good read and that can explain why the drive is very slow, but not dead (yet).

I tend to treat these cases as though every time it powers up and is able to output some data, it may be the very last time that it ever will. 

Andrew


--- On Thu, 7/16/09, James Watts <wattage@...> wrote:

From: James Watts <wattage@...>
Subject: Re: [Bug-ddrescue] When will ddrescue return to warp speed?
To: "Antonio Diaz Diaz" <ant_diaz@...>
Cc: bug-ddrescue@...
Received: Thursday, July 16, 2009, 7:22 AM

Hi Antonio. Thanks for the reply. I tried both of your suggestions. No change in results. It still refuses to exceed 300-500 KB/s.

I shut down and powered off the computer and both drives multiple times. I restarted ddrescue multiple times.

Any other thoughts? I just don't understand why it would initially recover so quickly and now it just refuses...

Thank you,

James

On Wed, Jul 15, 2009 at 12:26 PM, Antonio Diaz Diaz <antonio_diaz@...> wrote:

James Watts wrote:

I am currently rescuing a 500GB drive. When I first started ddrescue, the
routine began recovering data at the blistering rate of 18-20 MB/s. Then it
encountered an error (after recovering about 20GB) and the drive got hung-up
and did not respond to commands. So I had to turn off the drive, turn it on
again, and restart ddrescue. Now, it's been going for two days holding at a
rate of 300-500 KB/s. It has not encountered any more errors according to
the on-screen info and the log (see below). So why will it not ramp up to
the high-speed from before? At this rate, it could take weeks to complete.

Did you only reset the drive (/dev/sdb) instead of rebooting the whole computer? Maybe the controller or even the kernel switched to a slower mode after the error.

Thoughts? Am I doing something wrong? What would you do differently?

If the reboot doesn't work, I would try to stop ddrescue and restart it at the next multiple of 64KiB. (The next position with four trailing zeros: 0xD2C290600 ==> 0xD2C2A0000).


Regards,
Antonio.

-----Inline Attachment Follows-----

_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue

---

Looking for the perfect gift? Give the gift of Flickr!
_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue