Jim,

The 174 errors could be from another source.  Be sure to check your
/kernel/drv/st.conf file for the proper tape drvie entries.  I'm currently
wrestling with 174 errors because at some time in the past, these entries
were commented out on my media server, so we've been using the system
defaults.

Ken

-----Original Message-----
From: Bob Bakh [mailto:bbakh AT veritas DOT com]
Sent: Thursday, December 28, 2000 4:08 PM
To: David A. Chapa; Jim VandeVegt
Cc: NetBackup Veritas
Subject: RE: [Veritas-bu] NUMBER_ & SIZE_DATA BUFFERS


One thing you all might want to keep in mind is that your max on NT is a 64k
buffer.  I usually set it to 128 on a UNIX server, but if it is also running
Oracle or any other RDBMS, you may be in trouble with semaphores and shared
memory segments.  you may have to play with the /etc/system file or whatever
it is in your case to get it to work, you will normally get an status 11
error.  This is with most DLT 7000 drives.

On faster drives you can play with buffers of 128k 256k or 512, we don't see
much performance improvement over 256k

Good luck.

Bob 

-----Original Message-----
From: David A. Chapa [mailto:david AT datastaff DOT com]
Sent: Monday, December 18, 2000 10:30 AM
To: Jim VandeVegt
Cc: NetBackup Veritas
Subject: Re: [Veritas-bu] NUMBER_ & SIZE_DATA BUFFERS


Jim:

Before I would change the NUMBER and SIZE, I would 
create a bptm logging directory.

/usr/openv/netbackup/logs/bptm

this should be created on each of your media servers 
(including any master that has netbackup controlled 
devices).

this log will let you know how your buffer situation 
looks.

For one of my clients, I have found that the defaults 
were just about fine, with a slightly different 
orientation.

instead of the 8x64 I tried 16x32 (most of the backups 
use multiplexing).  This increased the speed quite a 
bit and using the bptm logging directory you are able 
to measure those results accordingly.

My 2 cents.

David Chapa

Quoting Jim VandeVegt <vandevegt AT yahoo DOT com>:

> Can other readers share what your NUMBER and 
SIZE_DATA_BUFFERS are in
> /usr/openv/netbackup/db/config?
> 
> My master server is a Sun 450, 1 GB RAM, 2x 400 MHz 
processing. 
> Shared Memory MAX is set to 1GB in /etc/system. Six 
tape drives.
> 
> I recently noticed my backups were going pretty slow 
and I realized I
> didn't have these two files in place, thus I was 
using the default
> 8x32KB buffers. I remembered from my NetBackup class 
that almost
> everyone increases the size of the buffers and 
usually decreases the
> numbers, but maintains a great increase in the total 
size of the
> buffer (size times number).
> 
> I tried 4 buffers 1048576 bytes (2^20 = 1 MB) big. I 
noticed a
> speedup in backups, but some NT clients started 
throwing errors.
> 
> Most of the errors are 174, a media manager error, 
which doesn't make
> a lot of sense; and a few error 41 (network 
connection timeout).
> 
> But I haven't fully diagnosed the errors net in the 
log files. I'm
> more interested in what other installations use for 
the buffer settings.
> 
> =====
> Jim VandeVegt
> vandevegt AT yahoo DOT com vandevegt AT avaya DOT com
> http://members.xoom.com/vandevegt
> Toilet paper should come off the front!
> 
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
David A. Chapa
Consulting Manager
DataStaff, Inc.
847 413 1144
_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
_______________________________________________
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