On Friday 24 January 2003 12:11, Jean-Francois Malouin wrote:
>Hello,
>
>* Martin Oehler (martin.oehler AT gmx DOT net) [20030124 11:52] thus 
spake:
>> Hi, Jon!
>>
>> Am Fre, 2003-01-24 um 16.27 schrieb Jon LaBadie:
>> > Maybe you hit what Gene describes in another posting today.
>> > Once a tape has been written to with HW compression, the drive
>> > senses it and automatically switches to HW compression
>> > regardless of settings.
>>
>> No, I made a mistake (see my reply to Genes posting).
>>
>> > What capacity were you expecting for "native", uncompressed
>> > data?
>>
>> I expect 100 GB. The drive specifications can be found at:
>> http://www.storage.ibm.com/hardsoft/tape/3580/prod_data/g225-685
>>4.html We use the internal version of the drive.
>>
>> > According to docs/TAPETYPE:
>> >
>> >    The speed is currently unused.
>> >
>> > Is this an HP drive by any chance?  ISTR they have some
>> > auto-slowdown system to match scsi-bus speed.
>>
>> # cat /proc/scsi/scsi
>> Attached devices:
>> Host: scsi1 Channel: 00 Id: 04 Lun: 00
>>   Vendor: HP       Model: Ultrium 1-SCSI   Rev: N23D
>>   Type:   Sequential-Access                ANSI SCSI revision:
>> 03
>>
>> If the measured size and filemark is correct, do you have an
>> idea how I will be able to use the drive with 15MB/sec?
>
>That all depends on your scsi or FC controller and pci bus.
>
>I have 4 Seagate LTOs in a STK_L40 library connected to
> differential scsi controler -- one for each drive. diff scsi
> because of cabling issues: LVD is a little less sturdy than
> differential scsi but that's besides the point. I have an O3800
> so I can shove 60MBs doen its throat no problem. In your case you
> have to ask yourself: is my pci bus wide and fast enough to
> sustain 15MBs?
>
>Here's my tapetype for my Seagate Ultrium:
>
>define tapetype Ultrium-SGT-LTO {
>    comment "just produced by tapetype program"
>    length 101376 mbytes
>    filemark 0 kbytes
>    speed 15084 kps
>    lbl-templ
>}
>
Thats a bit odd for what is supposed to be the same (geneticly 
speaking) drive.  I'm noteing that Martins drive claimed it needed 
a 545 kilobyte filemark.  That, to me with zero experience with 
either drive, still seems highly excessive.

Comments anybody?

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
99.22% setiathome rank, not too shabby for a WV hillbilly