Debbie,
One of the things that may be misleading by doing a
tar test is the read performance of the disk that the
tar file is on.  You can use the dd command with
if=/dev/zero to stream null characters from memory to
the device.  Example

dd if=/dev/zero of=/dev/rmt1 bs=1024 count=1000

This will write 1 MB of data to this device.  Precede
the string with timex to see how fast you can write
the file.  Adjust the block size and count to create
larger data stream.

I would be very interested in seeing what kind of
performance you are getting from these drives.


--- "Weeks, Debbie" <debbie AT ADMIN.USF DOT EDU> wrote:
> I have not been monitoring the list for a while, so
> I have not been monitoring the list for a while, so
> forgive me if I ask
> something that has been covered previously...
>
> We recently upgraded our 3466 model A01 with two
> 3575 tape libraries to a
> 3466 model C01 with a 3584 tape library.  We also
> upgraded from ADSM 3.1.1
> to TSM 4.1.  I have begun to notice that our tape
> operations are taking
> significantly longer than they did before.  Simple
> restores take forever
> between the mount and the start of data transfer,
> the time it takes to
> backup our DB has tripled (and the DB is smaller),
> and restores of large
> Oracle and Exchange databases are taking about twice
> as long.  The process
> of backing data up to the copypool for offsite
> storage is also taking a very
> long time.  I have a process running now that has
> backed up 21Gb from one
> tape in the primary pool to one tape in the
> copypool, in other words a
> straight tape to tape copy, over a two hour time
> period.
>
> Does anyone out there have any similar experience?
> We do have support from
> both Tivoli and IBM hardware support, any
> suggestions on who to call first?
>
> Debbie Weeks
> University of South Florida
> Information Technologies/Technical Support
> ********
> *Debbie AT ADMIN.USF DOT EDU
> *(813)974-6926*S/C 574-6926
> Fax (813) 974-3054


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