Re: Question on Tape Density, etc...

[Chuck Lewis <CLEWIS@xxxxxxxxxx>]

UNREAL !!!

Thank you SO MUCH for this information Neil - it is what I was looking for to
truly understand this thing...

I had been initializing tapes as 2GB (that is what the device DEFAULTS to...)...

I saved a library on a tape initialized at 2GB and it took 17 minutes.

I reinitialized the tape to 5GB and did the save again and it took 2 minutes
!!!!!!

While this isn't TOTALLY scientific, it is pretty close - the system I am doing
this on is not "live" yet and everyone was at lunch with NOTHING running in 
batch
of anything...

You are a LIFESAVER Neil !!!

Thanks,

Chuck

Neil Palmer wrote:

> The 9427 can store 7/14GB per tape - requiring the 160 meter length
> tapes and using *FMT7GB.
> Using 112m tapes the density is *FMT5GB - actually same density as
> *FMT7GB but a shorter tape.
> For backwards compatibility you can use the *FMT2GB, which will store
> 2.3GB (or 2.5 - depensing on who you believe) on a 112m tape (not on
> 160m tapes).
> You should not use *FMT2GB unless you need backwards compatibility, as
> you will cut the data transfer rate in half and increase the time
> required for backup.
>
> Neil Palmer         DPS Data Processing Services Canada Ltd.
>                                              AS/400~~~~~
> Thornhill, Ontario,  Canada    ___________          ___  ~
> Phone: (905) 731-9000  x238   |OOOOOOOOOO| ________  o|__||=
> Cell.: (416) 565-1682  x238   |__________|_|______|_|______)
> Fax:   (905) 731-9202          oo      oo   oo  oo   OOOo=o\
> mailto:NeilP@DPSlink.com    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> http://www.DPSlink.com        AS/400  The Ultimate Business Server
>
> -----Original Message-----
> From:   Chuck Lewis [SMTP:CLEWIS@IQUEST.NET]
> Sent:   Tuesday, September 29, 1998 10:46 AM
> To:     MIDRANGE-L@midrange.com
> Subject:        Question on Tape Density, etc...
> Importance:     High
>
> Hi Folks,
>
> Back to this 9427-210, before I call IBM...
>
> This LOOKS long but is somewhat deceiving (has lots of details for you
> help <BG>)...
>
> In my backup CLP I do a CHKTAP at the begining of the process and all
> is
> fine.
> The SAVLIB rolls along and completes OK.
>
> I do another CHKTAP and get the following message:
>
> CPF4024    Diagnostic              10    09/19/98   00:08:35   QTAERR
>
> Message . . . . :   Volume 000016 on device TAP01 is density *FMT2GB.
>
> Cause . . . . . :   The output volume is a different density than
> specified for file QSYSTAP in QSYS. Either the existing data files, or
> the labels on the volume may determine the volume density, or the tape
> device may not be able to process requested density. The density of the
> tape volume is used instead of the density in the tape device file.
>
> Recovery  . . . :   If the labeled tape density is not acceptable,
> prepare the tape with the correct density (INZTAP command), and then
> try
> the request again.
>
> File QSYS/QSYSTAP shows as follows:
>
> Tape density  . . . . . . . . . . . . . . . : DENSITY    *DEVTYPE
>
> So the questions:
>
> 1) Device TAP01 shows NOTHING related to Tape Density (????). Any idea
> WHAT's going on ?
>
> Everything works OK but I want to know if I'm missing something !
>
> 2) WHAT should this tapes be initialized as ? I'm using
> DENSITY(*FMT2GB)
> using Maxell HS-8/112 Helical-Scan 8mm Data Catridges.
>
> 3) They SAY the "nominal" capacity is 2.5/5.0 Gigabytes.What is the
> 9427
> capable of ?
>
> Thanks !!
>
> Chuck
>
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