Very slow certance lto-2 ultrium - SOLVED

[John R. Schleigh IV]

On Thursday 10 July 2008 06:31, Rarach wrote:
> Hi John,
>
> I think it's OK, sustained transfer speed of this model is 26MB/s.
> http://support.euro.dell.com/support/edocs/stor-sys/110TL_Ce/en/ug/specs.ht
>m
>
> I have same drive and my aprox.speed is close 20MB/s
>
> Vladimir
>
> 2008/7/9 John Schleigh <johns at networkamericainc.com>:
> > I have seen some mention of this, but no solutions yet.
> >
> > Can someone help me to understand what I need to do to get better than
> > 2.7Mb/s transfer rate on this Certance Ultrium 2 tape drive?  It should
> > be able to get closer to 20Mb/s.
> >
> > I have been guessing that I need to set the right blocking factor or
> > something, but I really don't know.  I have tried piping tar to mbuffer,
> > large block sizes, small block sizes.  Regardless, my shoes are very
> > shiny.
> >
> > # mt -f /dev/nst0 status
> > drive type = Generic SCSI-2 tape
> > drive status = 1107296256
> > sense key error = 0
> > residue count = 0
> > file number = 0
> > block number = 0
> > Tape block size 0 bytes. Density code 0x42 (unknown).
> > Soft error count since last status=0
> > General status bits on (41010000):
> >  BOT ONLINE IM_REP_EN
> >
> > Linux pe2900 2.6.16.46-0.12-smp #1 SMP Thu May 17 14:00:09 UTC 2007
> > x86_64 SLES 10
> >
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The aic7902 was set to 320Mb/s for the tape drive.  I set it to 160Mb/s and 
all is good.

I suppose that is a lesson to verify the hardware configuration after 
receiving a new server.

-- 
John R. Schleigh IV
Chief Technology Officer
Network America, Inc.
(571) 292-5828 ext 106
fax: (757) 295-5511