Seagate FreeAgent GoFlex 1.5TB external HDD problems

[maxim naumov]

ok, done some more testing and measured throughput FreeBSD vs.
GNU/Linux as you suggested:

# dd if=/dev/da0s1 of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes transferred in 33.181306 secs (32359842 bytes/sec)

and

# dd if=/dev/sdb1 of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 33.2969 s, 32.2 MB/s

I was doing more testing with dt, specifying different maximum and
minimum block sizes for random transfers. the curious thing is that I
could not fail it if the maximum block size is up to 16k. 32k and
higher eventually kills it. it seems to require random transfer size
to fail. the filesystem driver will do the same. doing just dd/dt with
a specified bs works fine. also I haven't seen it fail with a transfer
size smaller than 32k before. could this be something to do with the
USB transfer size of 64k (32k of data plus umass command)?

/max