Seagate FreeAgent GoFlex 1.5TB external HDD problems

[Hans Petter Selasky]

On Monday 02 July 2012 22:07:57 maxim naumov wrote:
> 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)?

Hi,

For High Speed, the software size limit is 64KBytes, because many devices 
don't support more.

--HPS