>
>Sun says not to install externals on the builtin F/W SCSI port on the
>I/O board in slot in becasue it controls the scsi devices (cd, tape) in
>the system cabinet. If you only have a CD and tape in the cabinet,
>there are other scsi targets left. Why can't other externals be hung
>off this F/W Scsi connection? Is it a cable length issue? Is anybody
>successfully using this connection for externals?
>
>Scott Tinsley Phone: 703-904-4340
>Systems Engineer Fax: 703-834-6922
>The Allied Group, Inc. Email: tinsley@tag.com
Two issues came out on use of the first I/O board f/w scsi
1) conflict with other devices and related perfromance issues
On the E4000 and up servers, the scsi only has a CD and maybe a 4mm, so
adding one more tape device doesn't seem like a problem.
2) Possible cable length restriction.
Becasue of the amount of cable in the system cabinet, adding an external
device may be a stretch. However, I have an E6000 with a working external
9tk of the first i/o board scsi and it works fine. There are others
in the mail below that appear to have also succesfully hung externals
of the first i/o board.
Thanks to all who responded.
Scott Tinsley Phone: 703-904-4340
Systems Engineer Fax: 703-834-6922
The Allied Group, Inc. Email: tinsley@tag.com
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>From mstier@hotmail.com Fri Apr 18 10:53:02 1997
X-Originating-Ip: [167.254.240.44]
From: "Matthew Stier" <mstier@hotmail.com>
To: tinsley@tag.com
Subject: Re: I/O Board 1 use on Enterprise server
Date: Fri, 18 Apr 1997 07:51:08 PDT
Adding external devices can (read "not will") effect system performace and
reliability due to device interaction.
For the shear ability to isolate potential problems, it is always best to attach
external devices onto their own buses. However, this is not mandatory.
-- Matthew Stier mstier@hotmail.com--------------------------------------------------------- Get Your *Web-Based* Free Email at http://www.hotmail.com ---------------------------------------------------------
----- End Included Message -----
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>From rtrzaska@uk.mdis.com Fri Apr 18 11:08:55 1997 Date: Fri, 18 Apr 1997 16:05:47 +0100 From: rtrzaska@uk.mdis.com (Ray Trzaska) To: tinsley@tag.com Subject: Re: I/O Board 1 use on Enterprise server Content-Md5: baoKyojV6PKnd7g52I7EkQ==
you guessed correctly, it is a cable length issue. Looking inside the E5000 cabinet, the io-board goes to the back of the box, and the cd/tape prestation is at the front, so there is roughly .75m cable run somewhere there. the cable from the prestation at the front of the cpu-box to the tape/cd in the front panel is the standard 1.2m cable.
So the first io/board internal scsi is already handling a 2m cable run which is as near to the limit as you would want. ( I am managing to run another tape here by balancing the tape on the bock and useing a .25m cable.)
ray.
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>From sweh@mpn.com Fri Apr 18 11:20:17 1997 From: Stephen Harris <sweh@mpn.com> Subject: Re: I/O Board 1 use on Enterprise server To: tinsley@tag.com Date: Fri, 18 Apr 1997 16:19:25 +0100 (BST)
Speed...
If the tape drive is busy then access to disks is slow :-(
It can be done, but it's not recommended.
rgds Stephen
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>From iimrj@brightpoint.com Fri Apr 18 11:40:20 1997 Date: Fri, 18 Apr 1997 10:42:18 -0500 From: Matt Johnson <iimrj@brightpoint.com> To: tinsley@tag.com Subject: I/O Board 1 use on Enterprise server -Reply Content-Disposition: inline
>From what I have read it is a cable length issue. I was able to attach another device to it (SUN DLT 4000 drive) and have not had problems. I would not extend it past that. We have an UE 6000.
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>From larry@mitra.com Fri Apr 18 11:43:38 1997 Date: Fri, 18 Apr 1997 11:43:23 -0400 From: Larry Williamson <larry@mitra.com> To: tinsley@tag.com Subject: I/O Board 1 use on Enterprise server
Of course it can be done, Sun put a connector on the back panel.
I am doing it, and successfully, but I am nervous about it.
Although it works just fine, I suspect it compromises the reliablity of the primary scsi bus.
I have a DLT jukebox on this builtin SCSI port. There is no traffic near the machine, so I am not too worried. But I look forward to putting this on a second scsi bus.
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