[Bug-ddrescue] Transfer rate questions, again

[Nicholas Bendler]

So I'm dealing with a (presumably) damaged drive that has really slow
throughput right now:

address@hidden /root % hdparm -t /dev/sdb
/dev/sdb:
 Timing buffered disk reads:    2 MB in 56.59 seconds =  36.19 kB/sec

address@hidden /root % hdparm -t --direct /dev/sdb
/dev/sdb:
 Timing O_DIRECT disk reads:    2 MB in 17.39 seconds = 117.75 kB/sec

As you might expect, ddrescue without -d is averaging around the first
amount. No big deal, except that on a 400 GB disk we're talking months
of recovery time.

Since the direct mode numbers are 3 times better (which means say, a
week to 10 days to recover the 80GB partition that has data on it
instead of a month), I'm trying to achieve those speeds. However, when
I run ddrecuse 1.10 with the -d argument and small values for -c (as
suggested previously on the list), my average rate actually drops
below 10000 B/s. With no -c, it averages around 14000 B/s. I've tried
increasing -c as well, but ddrescue just says the whole thing is an
error and quits.

Any help or suggestions would be appreciated. (Also, if anyone has any
insight into what my drive's actual problem is, that would be helpful
as well. Right now "slowness" the only problem I can see - there are
no SMART errors.)