Re: [Bug-ddrescue] Slowdown after ~1 hour

[Hendrik Müller]

Totally forgot the start args:
ddrescue -f -n -v -b 4096 /dev/sda /dev/sdc /ddrescue/rescue.log

2016-06-17 10:58 GMT+02:00 Hendrik Müller <address@hidden>:

> Hello,
> I'am currently in the process of a poor man's LSI raid data recovery.
> After a power supply failure I had to replace the head stack assembly of
> the drive (Western Digital Red 3TB).
> The drive is now working again but I have the problem that ddrescue 1.21
> is copying with ~300kB/s for the first hours and then suddenly drops to
> ~1000B/s.
> Speed stay at this rate for ever, I had running this for over a week.
> However when interrupting ddrescue and start again immediately speed is
> again at ~300kB/s for ~1 hours and then drops again.
> It is not always exactly an hour, sometimes it already happens after 30
> minutes, sometimes after 3 hours.
> Anyway, the pattern is that after interrupting and starting again there is
> "full speed" again (drive is powered on the while time, no interrupt).
>
> First I tough that it might be because of my setup (Raspberry Pi 3, latest
> Raspbian + Firmware, two ASM1053 USB to SATA adapter) but the same happens
> on a regular x86 machine running SystemRescueCd and directly connecting the
> drives via SATA.
> I compiled ddrescue 1.21 in both cases by myself.
>
> Any idea what could be the problem here?
>