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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Log writer
<FONT face=Arial color=#0000ff
size=2>Uh.....67,676 kb. ? as in 67 MB? for a redo
log buffer? Is this a result
of our
new president being a texan?
<FONT face=Arial color=#0000ff
size=2>
On
your system,
<FONT face=Arial color=#0000ff
size=2>
1) one
by one add three (3) new groups of redo log files. Make them <SPAN
class=538280219-22032001>5MB in size,
each.
2)
ALTER <FONT face=Arial
color=#0000ff size=2>system switch logfile until all the old redo logs show
<FONT face=Arial color=#0000ff
size=2>INACTIVE <FONT face=Arial
color=#0000ff size=2>in V$LOG,
3)
ALTER system checkpoint;
4)
DELETE the 32MB log file groups. With prejudice. ( If they don't die, call in
Dick Goulet.)
5)
Edit the init.ora and make the log_buffer...oh...say 2M. Bounce the instance.
<FONT face=Arial color=#0000ff
size=2>
Let us
know what happens.
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>Please.
<FONT face=Arial color=#0000ff
size=2>
-
Ross
<FONT face="Times New Roman"
size=2>-----Original Message-----From: Kevin Kostyszyn
[mailto:kevin_at_dulcian.com]Sent: Thursday, March 22, 2001 1:23
PMTo: Multiple recipients of list ORACLE-LSubject: RE:
Log writer
<FONT face=Arial color=#0000ff
size=2>thanks Ross,
<FONT face=Arial
color=#0000ff size=2>MTS, I didn't know it was on? Isn't that just an
init.ora setting? I am looking in to finding out about the cache, but no
luck yet. The redo log buffer is 67,676 kb. Yes, this isn't some
normal little system where the duhvelopers are just querying the db, they are
constantly doing DML, lots of FTS. I have found so many indexes in the
USERS tablespace which puts them on the same HD as the tables they are
accessing. I move them, but somehow more seem to always
appear...hmmm..wonder why that is.
<FONT face=Arial
color=#0000ff size=2>But I am curious, when you say network/app tuning, what
exactly do you mean by that? I know that two disks aren't that great,
but not my idea, it was done before my dumbass got here, now I am just trying
to fix it. Everything else looks good on the system though,
library_cache hit ratio, buffer cache hit ratio all very high. It's just
this program occasionally, about every 10 minutes is telling me the logwriter
is a slouch.
<FONT face=Arial
color=#0000ff size=2>What about my other question though,
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2> MAXLOGFILES 32 MAXLOGMEMBERS
2 MAXDATAFILES 32 MAXINSTANCES 16 MAXLOGHISTORY 4764LOGFILE GROUP 11 (
'E:\ORACLE\ORADATA\JAVA16\RBS01.DBF', 'E:\ORACLE\ORADATA\JAVA16\USERS01.DBF', 'E:\ORACLE\ORADATA\JAVA16\TEMP02.ORA', 'E:\ORACLE\ORADATA\JAVA16\TOOLS01.DBF', 'F:\ORACLE\ORADATA\JAVA16\INDX01.DBF', 'E:\ORACLE\ORADATA\JAVA16\DR01.DBF', 'E:\ORACLE\ORADATA\JAVA16\SYSTEM02.DBF', 'E:\ORACLE\ORADATA\JAVA16\USERS02.DBF', 'F:\ORACLE\ORADATA\JAVA16\INDX02.DBF', 'F:\ORACLE\ORADATA\JAVA16\RADS3PROD.DBF', 'G:\ORACLE\ORADATA\JAVA16\RADS3PRODINDX.DBF', 'G:\ORACLE\ORADATA\JAVA16\RBSBIG.DBF', 'G:\ORACLE\ORADATA\JAVA16\RADS3PRODINDX2.DBF'<FONT face=Arial color=#0000ff
<FONT face=Tahoma
size=2>-----Original Message-----From: root_at_fatcity.com
[mailto:root_at_fatcity.com]On Behalf Of Mohan, RossSent:
Thursday, March 22, 2001 12:21 PMTo: Multiple recipients of list
ORACLE-LSubject: RE: Log writer
<FONT face=Arial color=#0000ff
size=2>Kev,
<FONT face=Arial color=#0000ff
size=2>Pure shot from hip:
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>I'd say you have more network/app response tuning than log
tuning. I'd
<FONT face=Arial color=#0000ff
size=2>say you have more disk tuning ( for table/index reads) than log
tuning. I
<FONT face=Arial color=#0000ff
size=2>would DEFINITELY turn the silly ass MTS off.
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>I'd find out how to make sure disk cache is 4 MB and is
writeBACK
<FONT face=Arial color=#0000ff
size=2>not writeTHRU. ( if either ) <SPAN
class=173211317-22032001>I'd have
questions about the controller, too, but.."later".
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>(You didn't tell me the size of the redo log
buffer...)
<FONT face=Arial color=#0000ff
size=2>
Of
course, having a two disk wonder (or whatever it is) is the
number
<FONT face=Arial color=#0000ff
size=2>one thing to work on.
<FONT face=Arial color=#0000ff
size=2>
In
any case, with your hardware, your system should easily be
able
to
handle a few users, in its sleep.
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>There's about two dozen little tweaks you can do to perk things up a
bit,
<FONT face=Arial color=#0000ff
size=2>but basically, your "rock and a hard place" is going to be a two disk
wonder
on
a single controller...
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>hth
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>Ross
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>
<FONT face="Times New Roman"
size=2>-----Original Message-----From: Kevin Kostyszyn
[mailto:kevin_at_dulcian.com]Sent: Thursday, March 22, 2001 11:31
AMTo: Multiple recipients of list ORACLE-LSubject:
RE: Log writer
<FONT face=Arial color=#0000ff
size=2>Jeez, Seagate Cheeta 18 and 36, 10k RPM
ahhh
UNFORMATTED CAPACITY (GB)
________________22.54 FORMATTED
CAPACITY (GB)
__________________18.21 AVERAGE
SECTORS PER TRACK ________________213 rounded
down ACTUATOR TYPE
____________________________ROTARY VOICE
COIL TRACKS
___________________________________167,008
CYLINDERS ________________________________6,962
user HEADS
______PHYSICAL______________________24
DISCS (3 in)
_____________________________12
MEDIA TYPE _______________________________THIN
FILM/MR RECORDING METHOD
_________________________PRML 8/9
PR4 INTERNAL TRANSFER RATE
(mbits/sec)________152 to 231
EXTERNAL TRANSFER RATE (mbyte/sec) _______40
Sync
Low Voltage Differential(LVD) _______80
Sync SPINDLE SPEED (RPM)
______________________10,025
AVERAGE LATENCY (mSEC)
___________________2.99 BUFFER
(/optional)
_______________________1MB/4MB
Read Look-Ahead,
Adaptive,
I believe the only
problem is that they are on one controller. However, this is not a
huge database, only about 3-4 users connected at a time, but lots of
DML. The machine is a Dell Precision 410 with a gig of Ram and dual
PIII 450's. I don't think that it's a huge problem, but it does keep
coming up. There are three log file groups of 32 MB's each and yes
the database is also spread accross these two platters.
<FONT
size=2>
Oh and the
results......YOINK!
<FONT
size=2>
<FONT face=Arial color=#0000ff
size=2>rdbms ipc
message
14980809SQL*Net message from
client
9595869pmon
timer
1880177virtual circuit
status
1877869smon
timer
1875449dispatcher
timer
1874318SQL*Net break/reset to
client
49746control file parallel
write
18026db file sequential
read
3947log file
sync
1456db file scattered
read
1017
<FONT face=Arial color=#0000ff
size=2>EVENT
TIME_WAITED----------------------------------------------------------------
-----------log file parallel
write
616Null
event
411library cache
pin
315refresh controlfile
command
292reliable
message
273rdbms ipc
reply
146control file sequential
read
108log file switch
completion
58SQL*Net more data to
client
45enqueue
27file
identify
24
<FONT face=Arial color=#0000ff
size=2>EVENT
TIME_WAITED----------------------------------------------------------------
-----------log file single
write
23latch
free
19SQL*Net message to
client
17file
open
16buffer busy
waits
13SQL*Net more data from
client
6direct path
read
5log file sequential
read
0db file parallel
write
0instance state
change
0direct path
write
0
<FONT face=Arial color=#0000ff
size=2>EVENT
TIME_WAITED----------------------------------------------------------------
-----------LGWR wait for redo
copy
0
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>Which ya think master Ross?
<FONT face=Arial color=#0000ff
size=2>
<FONT face=Arial color=#0000ff
size=2>Kev
<FONT
size=2><FONT face=Arial
color=#0000ff>
<SPAN
class=562192116-22032001>
<SPAN
class=562192116-22032001> -----Original
Message-----From: root_at_fatcity.com
[mailto:root_at_fatcity.com]On Behalf Of Mohan, RossSent:
Thursday, March 22, 2001 11:02 AMTo: Multiple recipients of
list ORACLE-LSubject: RE: Log
writer
Disk mfr? rpm? <FONT
size=2>seek/access times? diskperf -y set
already? CPU,I/O, or diskbound system?
log buffer size? log file size? <FONT
size=2>what else is on the "separate" disks? anything? <FONT
size=2>separate disks share a controller? select
event, time_waited from v$system_event order by 2 desc; results?
just a few questions that come to mind....
-----Original Message----- From:
Kevin Kostyszyn [<A
href="mailto:kevin_at_dulcian.com">mailto:kevin_at_dulcian.com]
Sent: Thursday, March 22, 2001 8:50 AM <FONT
size=2>To: Multiple recipients of list ORACLE-L <FONT
size=2>Subject: Log writer
Hi all,
I am testing
out Spotlight on Oracle from Quest Software. It is telling
me that my log writer process is slow.
What it looks like it is saying is that most
disks take about 20ms to right the data and mine is taking on
average about 40ms. I don't know why, they
are scsi drives and there isn't that much stress
on the syste. Anyway, I moved the redo logs to seperate
disks, but I fear I may have made an
error. Instead of moving each "group" to <FONT
size=2>seperate hard disks, I moved the members of each group to
seperate hard disks. Anyway, I am
wondering if anyone has advice on this problem.
Sincerely, Kevin
Kostyszyn DBA Dulcian,
Inc www.dulcian.com <FONT
size=2>kevin_at_dulcian.com
-- Please see the official
ORACLE-L FAQ: <A target=_blank
href="http://www.orafaq.com">http://www.orafaq.com <FONT
size=2>-- Author: Kevin Kostyszyn
INET: kevin_at_dulcian.com
Fat City Network Services -- (858)
538-5051 FAX: (858) 538-5051 San Diego,
California -- Public Internet
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Received on Thu Mar 22 2001 - 13:38:18 CST
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