Subject: RE: Simple Question: dump params. for TK50?
To: 'Jonathan Sturges' <jonathan@cc.odu.edu>
From: Gunnar Helliesen <gunnar@bitcon.no>
List: port-vax
Date: 02/12/1997 22:31:33
I hope DEC forgives me for posting this, but here goes:

>From the 'dump' man page on Digital Unix 3.2c:

  -b blocks_per_write
            Specifies the number of blocks in 1024 bytes to write to the
            storage medium.  The default write block value is 10 blocks
(or
            10 kilobytes).  In many instances, increasing the number of
            blocks per write will increase your dump performance.  For
            optimal results on Digital's platform, use a value that is
            greater than or equal to 32, is a multiple of 4, and is less
than
            65.

[snip...]

       ___________________________________________________
       Tape Device   Density    Size           Size
                      (bpi)    (feet)   (1024-byte blocks)
       ___________________________________________________
       TA78             6250     1925               141056
       TA79             6250     1925               141056
       TA81             6250     1925               141056
       TA90            38000      436               194560
       TA91            38000      436               194560
       TF30             6667     1182                92416
       TF70            10000     2457               287948
       TF70L           10000     2457               287948
       TK50             6667     1182                92416
       TK70            10000     2457               287948
       TKZ09           54000     7456              4718592
       TLZ04           61000     1584              1132646
       TLZ06           61000     2640              1887436
       TS05             1600     2075                38912
       TU77             1600     2075                38912
       TU78             1600     2075                38912
       TU80             1600     2075                38912
       TU81             1600     2075                38912
       TU81E            1600     2075                38912
       TZ05             1600     2075                38912
       TZ07             1600     2075                38912
       TZ30             6667     1182                92416
       TZ85            42500     4925              2453299
       TZ857           42500     4925              2453299
       TZK08           54000     3276              2073600
       TZK10           16000     2580               483840
       ___________________________________________________


Gunnar

--
Gunnar Helliesen   | Bergen IT Consult AS  | NetBSD/VAX on a uVAX II
Systems Consultant | Bergen, Norway        | '86 Jaguar Sovereign 4.2
gunnar@bitcon.no   | http://www.bitcon.no/ | '73 Mercedes 280 (240D)


>-----Original Message-----
>From:	Jonathan Sturges [SMTP:jonathan@cc.odu.edu]
>Sent:	Wednesday, February 12, 1997 10:06 PM
>To:	port-vax@NetBSD.ORG
>Subject:	Simple Question: dump params. for TK50?
>
>This may be not exactly NetBSD... but here goes.
>
>What are the _proper_ parameters for 'dump' for a TK50?  I'm referring to 
>the 'bds' flags:  blocking factor, density, size.
>
>I just realized I think I've been doing backups with the 'dump' defaults, 
>which I think are pretty horrible (at least, they are in other BSD systems).
>I'd like to pack those tapes if I could... I know they're supposed to 
>hold 91Mb or so...
>
>thanks,
>Jonathan
>