Shannon Hendrix writes:
> I'm interested in hearing from anyone who uses DAT drives on a DPT SCSI
> controller, preferrably with FreeBSD 4.1 and an Intel system.
>
> I find the speed is very slow, and I know in the past these drives were fine
> with FreeBSD, though I can't remember which release now. With my most recent
> install of FreeBSD 4.1, I am lucky to get 3MB/minute on a drive and controller
> combination that I know can hit 45MB/min.
>
> Right now, with NetBSD on an old Sparc 5, they still get 20MB/min or better.
>
> No errors, even large restores are perfect, but take many hours to finish.
>
> The controller I have is a DPT-2044W, and it currently has the ROM version DPT
> suggested for use with tape drives. The drives in question are an Archive
> Python 4-tape robot and a Seagate Scorpion. Both are DDS2 drives.
I have DDS4 Seagate (IBM) streamer.
When I do 'dump something > /dev/sa0'
then write is by 1K blocks.
The read spead of such a tape is very slow;
'dd if=/dev/sa0 of=/dev/null bs=something' is about 200 Kbyte/sec
Just do 'dump something | buffer -s 64K > /dev/sa0'
and read from such tape is normal (more than 2 Mbyte/sec, depends on compression)
> No load on the DPT except for tapes and a CD-ROM burner.
I have 2940UW with lot of devises - I think that low read speed
with little blocks is not controller dependant.
> I haven't been able to find much information on this particular setup, and
> most tape woes seem error related, or related to another platform.
--
@BABOLO http://links.ru/
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
