topic Re: adding multiple tapedrives in Operating System - HP-UX

adding multiple tapedrives

Ceesjan van Hattum — Thu, 07 Nov 2002 12:20:38 GMT

Hi,
I'm to lazy to change DDS-tapes in the weekend. But for now we have no tape-robot. How many tapeunits i can add on the same scsi-chanin before putting the terminator ?
Is it just 8, like c2t0d0 to c2t7d0 ?

Regards,
Ceesjan

Re: adding multiple tapedrives

Vicente Sanchez_3 — Thu, 07 Nov 2002 12:25:17 GMT

Hi Ceesjan,

I depends on the scsi bus.

With SE SCSI the number is 7 ( 0 to 6) devices.

With FW SCSI the number is 15 ( 0 to 6 and 8 to 15) devices.

Regards, Vicente.

Re: adding multiple tapedrives

V. Nyga — Thu, 07 Nov 2002 12:34:13 GMT

Hi Ceesjan,

my (old) 'Installing Peripherals' handbook says:
All devices should have a unique bus address between 0 and 6. The bus address 7 is reserved for the SCSI interface. Do not use it for SCSI devices.

Regards
Volkmar

Re: adding multiple tapedrives

John Palmer — Thu, 07 Nov 2002 12:37:33 GMT

Single ended SCSI allows eight devices but your server uses one (normally .7 which is the highest priority) so you're limited to seven devices(.0 to .6).

FWD and Ultra SCSI, allows sixteen. .8 to .15 and .0 to .7 (in priority order lowest to highest), the server uses .7 again so you can have 15 devices.

Regards,
John

Re: adding multiple tapedrives

Leif Halvarsson_2 — Thu, 07 Nov 2002 12:38:58 GMT

Hi

Also check the switch on the tape drive. If is is a narrow SE unit there is only possible to select 0-7 (dont't use 7).

Re: adding multiple tapedrives

Eugeny Brychkov — Thu, 07 Nov 2002 12:53:29 GMT

Ceesjan, terminators must be connected at the ends of SCSI bus. In most cases controller is one of 'ending' devices and have trmintation sutned on. Termination rule is not dependent on how many and which devices (tapes, disks) do you have. Terminator(s) should be of correct type for the bus (SE, Diff, LVD)
Eugeny

Re: adding multiple tapedrives

A. Clay Stephenson — Thu, 07 Nov 2002 14:28:44 GMT

This sounds like your are running SE-SCSI; if so, be careful not to exceed the maximum bus length of 6m including all internal connections.