Strange:
looking at v$backup_async_io found some datafiles
where
active bytes per sec
long-waits
2154608
297
7489829
297
How can I start finding the disparity?
-----Original Message-----
From:
Stankus, Paula G
Sent: Tuesday, June 03, 2003 9:05
PM
To: Stankus, Paula G;
'[EMAIL PROTECTED]'
Subject: RE: Good technical
documents/references on tuning restores
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.....
-----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
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...
-----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
Okay, almost 4 minutes for a datafile that was 78168
blocks - how do I know if this is reasonable?
Also, seems to write these files out (restore sychron.)
why can't it restore different datafiles in parallel? - stupid
question huh?
-----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
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.
-----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
Also found on monitoring performance of RMAN jobs:
Note:144640.1 on Metalink
-----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
Found this white paper:
http://otn.oracle.com/deploy/availability/pdf/rman_performance_wp.pdf
Anything better?
-----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
This is what I have set on my target database:
----------------------------------- -------
-------------------
backup_tape_io_slaves
boolean
FALSE
tape_asynch_io
boolean
TRUE
Version 8.1.7.4 database and RMAN catalog - 32 bit
Networker MML
Using RAID
1+0
Solaris 2.8
-----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
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.
-----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
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.
Thanks,
Paula
