Veritas-bu

[Veritas-bu] NBU Data Buffer sizes

2001-05-07 23:33:38
Subject: [Veritas-bu] NBU Data Buffer sizes
From: tallen201 AT hotmail DOT com (Tim Allen)
Date: Mon, 07 May 2001 23:33:38 -0400

>From: "David A. Chapa" <david AT xbpadm-commands DOT com>
>Reply-To: "David A. Chapa" <david AT xbpadm-commands DOT com>
>To: Tim Allen <tallen201 AT hotmail DOT com>
>CC: david AT xbpadm-commands DOT com, Veritas-bu AT mailman.eng.auburn DOT edu
>Subject: Re: [Veritas-bu] NBU Data Buffer sizes
>Date: Mon, 7 May 2001 13:06:17 -0700 (PDT)
>
>Perfect is an absolute...unfortunately in tuning there
>are no absolutes ;-)
Alright...alright. ;)
>
>Are you multiplexing?
No

>What tape device are you using?
Four dlt7000 tape drives

>What's the IO to the tape device?
2000 - 4000Kbytes/sec.
I was seeing 7000 - 8000Kbytes/sec 4 weeks ago.

>What's your network speed?
We're using Gigabit ethernet.

>
>
>Quoting Tim Allen <tallen201 AT hotmail DOT com>:
>
> >
> > It doesn't wait for a full buffer quite as often as
>it waits for an empty
> > buffer though.
> >
> > Example:
> > ...
> > waited for empty buffer 462164 times, delayed 466388
>times, read 40990432
> > Kbytes
> > ...
> > waited for full buffer 1100 times, delayed 12622 times
> > ...
> >
> > So in this case, wouldn't growing the buffer or
>number of buffers possibly
> > help?  Waiting for empty buffer would mean there is
>more data coming from
> > the network than the drive(s) can handle.
> >
> > If everything is working perfectly, would the bptm
>logs contain no entries
> > for "waited for full" or "waited for empty" buffer?
> >
> >
> >
> >
> > >From: "David A. Chapa" <david AT xbpadm-commands DOT com>
> > >Reply-To: "David A. Chapa" <david@xbpadm-
>commands.com>
> > >To: Tim Allen <tallen201 AT hotmail DOT com>
> > >CC: Veritas-bu AT mailman.eng.auburn DOT edu
> > >Subject: Re: [Veritas-bu] NBU Data Buffer sizes
> > >Date: Mon, 7 May 2001 09:05:25 -0700 (PDT)
> > >
> > >At first glance, it doesn't look like you should grow
> > >the data buffers, but look at your network.  Wait for
> > >Full buffer means it is waiting on the network...I'd
> > >check there first.
> > >
> > >
> > >
> > >Quoting Tim Allen <tallen201 AT hotmail DOT com>:
> > >
> > > > Hello.
> > > >
> > > > A database backup is taking a bit longer than
> > >expected, and I was
> > > > considering bumping up the data buffers.
> > > > SIZE_DATA_BUFFERS is currently 64512 and
> > >NUMBER_DATA_BUFFERS is 16.
> > > >
> > > > The bptm log has the following entries;
> > > >
> > > > 04:12:47 [12400] <2> fill_buffer: [12399] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 462164 times, delayed 466388 times, read
>40990432
> > >Kbytes
> > > > 04:12:47 [12399] <2> write_data: waited for full
> > >buffer 1100 times, delayed
> > > >
> > > > 1262
> > > > 2 times
> > > > 04:29:51 [12433] <2> fill_buffer: [12432] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 492546 times, delayed 498792 times, read
>43451936
> > >Kbytes
> > > > 04:29:51 [12432] <2> write_data: waited for full
> > >buffer 1206 times, delayed
> > > >
> > > > 1131
> > > > 1 times
> > > > 06:52:49 [13024] <2> fill_buffer: [13023] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 426891 times, delayed 430477 times, read
>37139232
> > >Kbytes
> > > > 06:52:49 [13023] <2> write_data: waited for full
> > >buffer 591 times, delayed
> > > > 10367
> > > > times
> > > > 07:45:18 [13096] <2> fill_buffer: [13095] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 543885 times, delayed 549783 times, read
>47816800
> > >Kbytes
> > > > 07:45:18 [13095] <2> write_data: waited for full
> > >buffer 930 times, delayed
> > > > 5408
> > > > times
> > > > 08:13:28 [13810] <2> fill_buffer: [13808] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 38963 times, delayed 103462 times, read
>2457696
> > >Kbytes
> > > > 08:13:29 [13808] <2> write_data: waited for full
> > >buffer 0 times, delayed 0
> > > > times
> > > > 08:48:43 [14012] <2> fill_buffer: [14011] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 38882 times, delayed 103166 times, read
>2457696
> > >Kbytes
> > > > 08:48:44 [14011] <2> write_data: waited for full
> > >buffer 0 times, delayed 0
> > > > times
> > > > 09:23:17 [14150] <2> fill_buffer: [14149] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 37823 times, delayed 100564 times, read
>2386784
> > >Kbytes
> > > > 09:23:18 [14149] <2> write_data: waited for full
> > >buffer 0 times, delayed 0
> > > > times
> > > > 09:54:18 [14302] <2> fill_buffer: [14301] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 34057 times, delayed 90351 times, read 2150432
> > >Kbytes
> > > > 09:54:19 [14301] <2> write_data: waited for full
> > >buffer 3 times, delayed 32
> > > >
> > > > time
> > > > s
> > > > 10:05:10 [13608] <2> fill_buffer: [13607] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 550854 times, delayed 557508 times, read
>46860128
> > >Kbytes
> > > > 10:05:10 [13607] <2> write_data: waited for full
> > >buffer 85 times, delayed
> > > > 2284 t
> > > > imes
> > > > 10:18:30 [13885] <2> fill_buffer: [13884] socket
>is
> > >closed, waited for
> > > > empty
> > > > buf
> > > > fer 421021 times, delayed 424891 times, read
>39006624
> > >Kbytes
> > > > 10:18:30 [13884] <2> write_data: waited for full
> > >buffer 597 times, delayed
> > > > 3158
> > > >
> > > >
> > > > There are more delays waiting for an empty buffer
> > >than a full buffer so I
> > > > was considering bumping the SIZE_DATA_BUFFERS to
> > >129024.
> > > >
> > > > Hmmm...  I guess the only reason for sending this
>e-
> > >mail was to ask if this
> > > >
> > > > sounds reasonable for what is in the bptm logs?
> > > >
> > > > I'll have to try it and find out if this improves
> > >anything next time.
> > > >
> > > >
> > > > Tim Allen
> > > >
> > > >
> > > >
> >
> >_______________________________________________________
>_
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> > > > _______________________________________________
> > > > Veritas-bu maillist  -  Veritas-
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> > > >
> >
> >http://mailman.eng.auburn.edu/mailman/listinfo/veritas-
> > >bu
> > > >
> > >
> > >
> > >
> > ><><><><><><><><><><><><><><><><><><><><>
> > >David A. Chapa
> > >Consulting Manager
> > >DataStaff, Inc.
> > >847 413 1144
> > >http://www.consulting.datastaff.com
> > >---------------------------------------
> > >http://www.xbpadm-commands.com
> > >NBU-LSERV AT datastaff DOT com - Adv. Scripting
> >
> >
>________________________________________________________
>_________
> > Get your FREE download of MSN Explorer at
>http://explorer.msn.com
> >
> >
>
>
>
><><><><><><><><><><><><><><><><><><><><>
>David A. Chapa
>Consulting Manager
>DataStaff, Inc.
>847 413 1144
>http://www.consulting.datastaff.com
>---------------------------------------
>http://www.xbpadm-commands.com
>NBU-LSERV AT datastaff DOT com - Adv. Scripting

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