X-no-Archive:yes
Hum, the DLT4000 probably used a single-ended FAST SCSI-2 connection. Has
anyone been able to boot an HP 3000 from a DLT 7000 over a differential F/W
SCSI connection? I have been told by HP this is not supported for boots or
installs. I would be very happy if it were possible as some of our customers
are looking at DLT libraries as a backup device.
Kind regards,
Denys. . .
Denys Beauchemin
HICOMP
(800) 323-8863 (281) 288-7438 Fax: (281) 355-6879
denys at hicomp.com www.hicomp.com
-----Original Message-----
From: Gilles Schipper [SMTP:[log in to unmask]]
Sent: Monday, 27 September, 1999 7:24 PM
To: [log in to unmask]; [log in to unmask]
Subject: Re: [HP3000-L] PowerPatch 7 DDS3 and SLT
No doubt it is true that DDS3 tape drives cannot output to non-125-metre
tapes in DDS3 format.
However, I have a DDS3 tape drive that I can happily boot from - using
60-metre, 90-metre, 120-metre or 125-metre tapes.
Having said that, however, it seems that when I use 90-meter tapes, I can
successfully boot from them about 50% of the time.
No problem, though, if I just keep trying, it works. Have not yet had a
situation where I have not been able to boot.
Perhaps it can said more accurately that you need 125-metre tapes to be
able to boot with almost 100% certainty.
The reasons I prefer to use 90-metre tapes for my backups (which always
include an SLT at the beginning) are:
1. I could my full backup tape to boot from my alternate DDS1 drive in the
event of a problem with the DDS3 drive.
2. I can restore any file to a DDS1, DDS2 or DDS3 tape drive (which most of
my customers have).
Regarding the absence of benefit in the absence of 125-metre tape on a dds3
drive, let me simply state that it makes almost no difference in speed. The
only real benefit would be in being able to fit more data on the tape
(apart from the higher boot success rate).
When I started doing my backups on the dds3 drive instead of my dds1 drive,
my backup time was cut in half - irrespective of the length of tape used.
Based on that experience, I would guess the same would be true of dds2 -
although I have no first-hand experimental data that would support that
conjecture.
Finally, who says we can't boot from DLT ?
>From my experience, this would be true of the older CIO machines - but
certainly not true of any of the NIO machines - which can very efficiently
be booted from an SLT tape created on a DLT4000. I cannot say that one can
boot from a DLT7000, since I haven't tried.
At 05:47 PM 1999-09-27 -0500, Denys Beauchemin wrote:
>X-no-Archive:yes
>Actually the problem goes beyond the MRS on the cartridge. Many people think
>they are saving money by buying 120 meters or smaller tapes for their DDS 3
>devices or 90 and 60 meters for their DDS 2 devices. They are actually
>cheating themselves. DDS 3 drives will only write at DDS 3 recording format
>when a 125 meter tape is used. Similarly a DDS 2 drive will only write at
DDS
>2 format when a 120 meter tape is used. If these tapes are not used, the
>device writes at DDS 1 in the case of the DDS 2 drive, and I believe, though
>uncertain that the DDS 3 will do the same. I am uncertain if the DDS 3 will
>write at DDS 2 format on a 120 meter tape. Either way, you lose the benefits
>of DDS 3 on a DDS 3 drive and the benefits of DDS 2 on a DDS 2 drive.
>
>So I can see where a 125 meter tape is required for booting from a DDS 3.
>
>Too bad we can't boot from DLT! :)
>
>Kind regards,
>
>Denys. . .
>
>Denys Beauchemin
>HICOMP
>(800) 323-8863 (281) 288-7438 Fax: (281) 355-6879
>denys at hicomp.com www.hicomp.com
>
>
>-----Original Message-----
>From: Steve Cole [SMTP:[log in to unmask]]
>Sent: Monday, 27 September, 1999 12:27 PM
>To: [log in to unmask]
>Subject: Re: PowerPatch 7 DDS3 and SLT
>
>Not to say that the following discussion is in anyway related to the
>described problem. There is a problem utilizing any DDS tape not labeled as
>"Media Recognition" in DDS3 drives. A number of the older 60m and 90m DDS
>tapes do not support this. If you have or planning to install a DDS3 drive
>you may want to check your old tapes to ensure they support "Media
>Recognition".
>
>Just a f.y.i.
>Steve
>
>=================================
>Steve Cole
>Outer Banks Solutions, Inc.
>[log in to unmask]
>www.outerbankssolutions.com
>Phone: 919.231.2171 Fax: 919.231.7077
>Sales: 800.558.5336
>=================================
>
>
>-----Original Message-----
>From: Brad <[log in to unmask]>
>To: [log in to unmask] <[log in to unmask]>
>Date: Monday, September 27, 1999 11:23 AM
>Subject: PowerPatch 7 DDS3 and SLT
>
>
>> We ran into a critical situation on 9/23/99 while updating our 929 to 5.5
>>PP7 with REACTIVE PATCHES using AUTOINST for the PP and AUTOPAT for the
>>reactives. To make a long story short, it turns out that the ISL> is
>>unable to read anything but a 125M DAT if you have a DDS3 drive during an
>>UPDATE when the SLT was made by AUTOPAT. It has now been recommended to us
>>by HP to use only 125M DATS for all SLT's as this problem may occur with
>>any SLT on other than125M DAT if using a DDS3 tape drive. This problem
>>caused us six extra hours of downtime.
>>
>> Brad Frondorf - Berks County 911
>
>
---------------------------------------------------------------------------
Gilles Schipper
GSA Inc.
HP3000 & HP9000 System Administration Specialists
300 John Street, Box 87651 Thornhill, ON Canada L3T 7R4
Voice: 905.889.3000 Fax: 905.889.3001
Internet: [log in to unmask]
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