Daizy chain

[Suresh Patoria]

Hi All,

I have 1 DLT 2/20 library and 1 ultrium
I want to do daizy chain.
i want to know daizy chain possible or not for the same
If possible then which cable is required for this.
Both the things are LVDS

whoever answer for this will get the highest points

Thanx in advance

[Suresh Patoria]

It is DLT 8000 drive

[Kurt Beyers.]

You can daisy chain it (but I would recommend a different SCSI controller for the Ultrium drive).

If you only have one controller, use the following chain:

SCSI-Ultrium-DLT8000_drive1-DLT8000_drive2-robot_arm

best regards,
Kurt

[Suresh Patoria]

Tahnx for the fast reply,

but i have one core scsi I/O in DLT

and i have seperate Ultrium so now tell how i should connect that.
what is length of the cable sould supported for daizy chain

Thanx

[Angus Crome]

I have one device on LVD that is 12 feet from initiator to device. You can probably go a little farther than that, but I wouldn't count on it.

As for Daisy chaining "Just say no". Find a means of getting a second controller. If you have to use it in the D.C. configuration, try very hard to use only one device at a time, and put the LTO first in the chain.

Reasoning;
If you use both simultaneously, it will kill the streaming effect of the technologies. This will 1) Degrade your throughput very significantly, 2) Prematurely wear out the drives and media in them.

[Suresh Patoria]

Hi,

We have FC card in DLT
it is acting as a bridge

DLT talking over fiber

how i connect Ultrium on DLT

Thanx

[Kurt Beyers.]

How many SCSSI ports do you have in your fibre switch? Normally you have two SCSI ports, I would do the following:

SCSI_port1-DLT_drive1-DLT_drive2-robot_arm
SCSI_port2_LTO_drive

But again, see that you cannot claim some resources for a dedicated SCSI controller for the Ultrium drive.

Kurt

[Suresh Patoria]

HI,

can i do like this


SCSI_port1-DLT_drive1-robot_arm SCSI_port2_DLT_drive2_LTO_drive

pls tell me which cable i should connect.
what length it is supported

Thanx

[Leif Halvarsson_2]

Hi,

Cable lenght depends on the type of SCSI interface (SE or LVD).

It makes a big difference if any of your devices is SE (Single Ended). If you are sure that all devices (and the HBA) is LVD the max length is 15 m. If any of the devices or the HBA is SE the max lenght is 3m (internal lenght should be included).

In your case daisy chaining is possible if all devices is LVD.

Note, if all devices is running concurrently you may get performance limitations with the Ultrium drive.

[Joshua Scott]

Order on the SCSI Bus does not matter whatsoever. make sure, however, the the ultrium drive gets a SCSI ID of 6 (highest priority) and that the 2 DLT Drives get higher than the robot arm. The priority is in this order, from high to low:

7,6,5,4,3,2,1,0,15,14,13,12,11,10,9,8.

The maximum length is 12m or 39ft.

Josh