RE: Good technical documents/references on tuning restores

From: Igor Neyman <ineyman_at_perceptron.com>
Date: Thu, 05 Jun 2003 00:59:56 -0700
Message-ID: <F001.005A9DA9.20030604063005@fatcity.com>

Paula,

It was very entertaining to read this thread -J

Did you answer all your questions?-J

<span

style='font-size:10.0pt;color:navy'>Igor Neyman, OCP DBA

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style='font-size:10.0pt;color:navy'>[EMAIL PROTECTED]

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style='font-size:10.0pt;font-family:Tahoma'>-----Original Message----- From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, June 03, 2003 9:05
PM
To: Multiple recipients of list
ORACLE-L
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Did I say that throughout this restore/recovery process my tapes being mounted and unmounted while other database backups and cloning was occurring. Big duh - this has got to be slowing down the process. Any ideas on how to handle this? Perhaps more than one tape subsystem would be better or while doing restores other backup utility is halted - hmmm - but that risks those other systems? How can I sell that? Hmmmm. Maybe I will first backup to disk. Yep, one backup to disk. Yep.....

<span

style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 9:00
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>See nwadmin shows parellism = 32. I am not the tape person - that is my sys admin. I don't believe they actually have 32 tapes involved only 4. Can this impact performance by setting this too high? I also notice one backup server for networker with nwadmin messages like "clone sets being created...", "other databases being backed up". What is the usual policy on concurrently running backups, cloning at the same time recovery is taking place. It appears to show a lot of media waiting events: waiting for dlt7000 tape ... of the tapes that I specifically need for this restore. Did I say: I love my admin...I love my admin....I love my admin...

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style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:53
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Okay, almost 4 minutes for a datafile that was 78168 blocks - how do I know if this is reasonable?

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style='font-size:10.0pt'>Also, seems to write these files out (restore sychron.) why can't it restore different datafiles in parallel? - stupid question huh?

<span

style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:46
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>SELECT SID, SERIAL#,

CONTEXT,

ROUND(SOFAR/TOTALWORK*100,2)
"%
complete",

SUBSTR(TO_CHAR(SYSDATE,'HH24:MI:SS'),1,15) "Time now"
FROM

V$SESSION_LONGOPS

WHERE OPNAME like

'%restore%';                          

.

showed all 100% complete but msglog
from RMAN shows it is truly still running.

<span

style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:40
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Also found on monitoring performance of RMAN jobs:

Note:144640.1 on Metalink

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style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:36
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Found this white paper:

<span

style='font-size:10.0pt'><a
href="http://otn.oracle.com/deploy/availability/pdf/rman_performance_wp.pdf" target="_blank">http://otn.oracle.com/deploy/availability/pdf/rman_performance_wp.pdf

<span

style='font-size:10.0pt'>Anything better?

<span

style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:33
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>This is what I have set on my target database:

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style='font-size:10.0pt'>----------------------------------- -------
-------------------

backup_tape_io_slaves
boolean
FALSE

tape_asynch_io

boolean
TRUE
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style='font-size:10.0pt'>Version 8.1.7.4 database and RMAN catalog - 32 bit

Networker MML
Using RAID 1+0
Solaris 2.8

<span

style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:28
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Okay - from my reading you don't need to have multiple tape io slaves if you are using asynch. I/O. Again, best document for perf. tuning database restores using RMAN would make mucho difference. Read old note about someone doing an analyze on the RMAN catalog tables to improve performance of restore. I think it has something to do with how quickly it finds the file on tape and writes to disk.

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style='font-size:10.0pt'>-----Original Message----- From: Stankus, Paula G
Sent: Tuesday, June 03, 2003 8:25
PM
To: '[EMAIL PROTECTED]'

Subject: RE: Good technical
documents/references on tuning restores

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style='font-size:10.0pt'>Seems to be taking awfully long to read files from tape and write to disk. I allocate multiple tape channels like I do for the backup which only takes about 45 minutes. Does not seem to be spawning multiple sessions. Do I need to change parameters on my init.ora file to use multiple tape io slaves to see this. Anyway, would like notes/docs., references if you all have some.

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style='font-size:10.0pt'>Thanks,
Paula Received on Thu Jun 05 2003 - 02:59:56 CDT