Joost! I apologize, we are indeed using LTO-1 tapes with LTO-1 drives and
LTO-2 tapes with the LTO-2 drives.
I should have made that statement in my issue header information. We are
going to try monkeying with the atdd_cfg info David C. pointed out. Thank
you so much for your expert advise. Aren
-----Original Message-----
From: Joost Mulders [mailto:mail AT j-mulders.demon DOT nl]
Sent: Friday, December 05, 2003 3:34 PM
To: mail AT j-mulders.demon DOT nl; Aren.Parisi AT wwireless DOT com
Cc: veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Where in NBU are drive settings (LTO-1 and LTO-2 )
tuned separatel y?
Hi Aren,
No, you don't need to install two different drivers for the LTO[12]
tapedrives.
You have LTO1 and LTO2 drives in your ADIC lib., right?
There are LT01 and LTO2 cartridges (tapes) on the market. LTO2 drives CAN
write
LTO1 cartridges, but with a "limited" speed of 20MB/s. To get 30 (or 35)
MB/s in
an LTO2 drive, you need to use LTO2 tapes in it. If you purchased your tapes
from IBM: LTO1 cartridges are black and LTO2 cartridges are purple.
Best regards, Joost
>Hello Joost,
>What do you mean by "LTO1 media"? We use the atdd driver, ver 3.1.0.3
>GES IBM magstar ultrium tape device driver, the devices show "CLAIMED"
>on ioscan to all of the LTO (1 & 2)devices with this software, are you
>telling me that with HP-UX you must install two separate drivers and bind
each by hand?
>-----Original Message-----
>From: Joost Mulders [mailto:mail AT j-mulders.demon DOT nl]
>Sent: Friday, December 05, 2003 1:09 PM
>To: veritas-bu AT mailman.eng.auburn DOT edu; Aren.Parisi AT wwireless DOT com
>Subject: Re: [Veritas-bu] Where in NBU are drive settings (LTO-1 and LTO-2)
>tuned separatel y?
>
>
>Hi Aren,
>
>Two notes on your question:
>
>1. Media
>Make sure you are using LTO2 media in your LT02 drives. With IBM drives
>(and I think the others as well), using LTO1 media in an LTO2 drives
>reduces the max.
>throughput to 20MB/s.
>
>2. SIZE_DATA_BUFFERS
>Make sure you have /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS
>file on your media server(s) with a value of 262144 (256K) in it. This
>file controls the size
>of the data buffers yadiyadiyadi, but also the blocksize used to transfer
>data
>to the drive. Using "big blocks" lowers SCSI/FC bus overhead (each block
has
>to
>be sent and acknowledged) and it improves the efficency of the compression
>algorithm in the drive: the larger the block, the more "similar" patterns
>can be
>found and compressed.
>
>The above is true for all tapedrives. There are no LTO2 specific knobs.
>
>joost
>
>
>>NBU 3.4.1 Master:HP-UX 11i three-way service guard cluster
>>Library:ADIC
>>scalar10k IBM Ultrium drives:20@LTO-1, 10@LTO-2 same cabinet. We have
>>just benchmarked our new LTO-2 drives and they are NO FASTER than the
>>LTO-1 drives. Are there separate tuneables for the new drives we are
>>not looking at? Buffer settings, something undocumented perhaps? We
>>have a 3GB (bound) FC ethernet connection on the media server so I
>>don't think it's a network bottleneck, disk is XP-512 (rebadged
>>Hitachi) screaming fast disk. Tested same class on each type of drive,
>>identical runtimes. ??? Thank you experts.
>>
>> Aren M. Parisi *
>> Information Technology
>> Western Wireless Corp.
>>(425)313-5225 mob.(206)795-6631
>> Where are we going and why am I in this handbasket?
>>
>
>--
>Long may you run.
--
Long may you run.
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