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How to slow down the SCSI bus speed on the rp7400

NTC
Regular Advisor

How to slow down the SCSI bus speed on the rp7400


Hello Guys,
Anyone has idea if we can slow down the SCSI bus speed of the HP rp7400 system??
We got an old tape drive (HP88780) that dont work with "dd" command & the tape drive company recommends to slow down the bus speed to about 5 to 10Mbits..

any ideas are appreciated

Suheil
9 REPLIES
Paula J Frazer-Campbell
Honored Contributor

Re: How to slow down the SCSI bus speed on the rp7400

Hi

The tape drive company have been smoking something they shouldn't.

The tape will only accept and receive data at its own speed and IT controls the speed of data.

Have you tried tar and cpio to the drive?



Paula
If you can spell SysAdmin then you is one - anon
Eugeny Brychkov
Honored Contributor

Re: How to slow down the SCSI bus speed on the rp7400

Suheil,
to change SCSI port speed stop machine in PDC and use SCSI command in configuration menu. This drive is SE drive, and if there're other device on the bus they will be forced to work in SE mode. Where did you get this drive? Are you sure this drive has appropriate firmware for hpux server?
Eugeny
Paula J Frazer-Campbell
Honored Contributor

Re: How to slow down the SCSI bus speed on the rp7400

HI

The HP88780 Front Load Tape Drive was released in June 1989

Data transfer rate

to/from tape
769 Kbytes/s (GCR) max.
208 Kbyes/s (PE)max.
104 Kbytes/s (NRZI) max.

http://www.cpuinc.com/88780.html


Paula
If you can spell SysAdmin then you is one - anon
NTC
Regular Advisor

Re: How to slow down the SCSI bus speed on the rp7400

Hi Paula,

This Tape drive isa mess, i worked hard to make it work but it did'nt, it is seen by the HPUX 11i system as "HP88780" and i can write/read on it with tar only with the option "b .." , whenever i use dd , i write with no errors adn i read with i/o read error (error number 2). HP they don tsuppot this drive anymore and some guys say we should change the firmware to be seen by unix as "HP7980", but the company of the drive says that they do slow down the SCSI bus on some intel machines & this made it work that is why im wondering if we can slow the SCSI bus of the rp7400 system..

tragic story is not it :)...
Thank you for ur msg
Suheil

NTC
Regular Advisor

Re: How to slow down the SCSI bus speed on the rp7400

Eugeny,

HOw can we be sure if this drive has appropriate firmware for hpux server?
ioscan sees it as HP88780 and tar works on it with the "b" option, dd roughly work with "I/O error but not all the time..

i will investigate more to change the scsi bus speed on the rp7400.

Thanx
Suheil
NTC
Regular Advisor

Re: How to slow down the SCSI bus speed on the rp7400

Hello Guys,

anyone is aware of a patch (or patches) to fix the "dd" command on hpux 11i ??
my dd on 11i is not reading on onay magnetic tape.

Thx
Suheil
Eugeny Brychkov
Honored Contributor

Re: How to slow down the SCSI bus speed on the rp7400

Run 'cstm', then the following commands:
'map', find drive in the list, note number in first column and
'sel dev ##' ## is this number
'info'
'il'
this command will display information for the device. Take it out there and post here
Eugeny
NTC
Regular Advisor

Re: How to slow down the SCSI bus speed on the rp7400

Thank you Eugeny,

I will post the information as soon as i go to the customer site and get this data.

Regards
Suheil
NTC
Regular Advisor

Re: How to slow down the SCSI bus speed on the rp7400

Hello There,

Just was at the site of tape drives, i tried to use the "cstm" to get info about the drives, it shows the device nb 7 as the "HP88780", but could not got more info coz when i run the tools within cstm it shows "disabled" ..for some reasons...
anyways i tried the mediainit command on the new tape & it comes with the error msg:

error in ioctl SET CMD MODE: mode sense: I/O error.

any ideas abotu this error will be appreciated. IF someone has the configuration parameters to be set on the HP88780 to work with HPUX 11 i woul dbe thankful.

Thx
Suheil