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
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?
No, you don't need to install two different drivers for the LTO
You have LTO1 and LTO2 drives in your ADIC lib., right?
There are LT01 and LTO2 cartridges (tapes) on the market. LTO2 drives CAN
LTO1 cartridges, but with a "limited" speed of 20MB/s. To get 30 (or 35)
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
>What do you mean by "LTO1 media"? We use the atdd driver, ver 220.127.116.11
>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?
>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?
>Two notes on your question:
>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.
>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
>to the drive. Using "big blocks" lowers SCSI/FC bus overhead (each block
>be sent and acknowledged) and it improves the efficency of the compression
>algorithm in the drive: the larger the block, the more "similar" patterns
>found and compressed.
>The above is true for all tapedrives. There are no LTO2 specific knobs.
>>NBU 3.4.1 Master:HP-UX 11i three-way service guard cluster
>>scalar10k IBM Ultrium drives:[email protected], [email protected] 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.
>> Where are we going and why am I in this handbasket?
>Long may you run.
Long may you run.