Multiplexing Online redo logs, archive logs, and control files.

Currently I am only multiplexing my control files and online redo logs, My archive logs are only going to the FRA and then being backed up to tape.
We have to replace disks that hold the FRA data. HP says there is a chance we will have to rebuild the FRA.
As my archive logs are going to the FRA now, can I multiplex them to another disk group? And if all of the control files, online redo logs and archive logs are multiplexed to another disk group, when ASM dismounts the FRA disk group due to insufficient number of disks, will the database remain open and on line.
If so then I will just need to rebuild the ASM volumes, and the FRA disk group and bring it to the mount state, correct?
Thanks!

You can save your online redo logs and archive logs anywhere you want by making use of of init params create_online_log_dest and log_archive_dest_n. You will have to create new redo log groups in the new location and drop the ones in the FRA. The archive logs will simply land wherever you designate with log_archive_dest_n parameters. Moving the control files off FRA is a little trickier because you will need to restore your controlfile to a non-FRA destination and then shutdown your instance, edit the control file param to reflect changes and restart.
I think you will be happier if you move everything off the FRA diskgroup before dismounting it, and not expecting the db to automagically recover from the loss of files on the FRA.

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Multiplexing redo logs and control files to a separate diskgroup

General question this one...
I've been using ASM for a few years now and have always installed a new system with 3 diskgroups
+DATA - for datafiles, control files, redo logs
+FRA - for achive logs, flash recovery. RMAN backup
Those I guess are the standards, but I've always created an extra (very small) diskgroup, called +ONLINE where I keep multiplexed copies of the redo logs and control files.
My reasoning behind this is that if there are any issues with the +DATA diskgroup, the redo logs and control files can still be accessed.
In the olden days (all those 5 years ago!), on local storage, this was important, but is it still important now? With all the striping and mirroring going on (both at ASM and RAID level), am I just being overtly paranoid? Does this additional +ONLINE diskgroup actually hamper performance? (with dual write overheads that are not necessary)
Thoughts?

Some of the decision will probably depend on your specific environment's data activity, volume, and throughput.
Something to remember is that redo logs are sequential write, which benefit from a lower RAID overhead (RAID-10, 2 writes per IOP vs RAID-5, 4 writes per IOP). RAID-10 is often not cost-effective for the data portion of a database. If your database is OLTP with a high volume of random reads/writes, you're potentially hurting redo throughput by creating contention on the disks sharing data and redo. Again, that depends entirely on what you're seeing in terms of wait events. A low volume database would probably not experience any noticeable degraded performance.
In my environment, I have RAID-5 and RAID-10 available, and since the RAID-10 requirement from a capacity perspective for redo is very low, it makes sense to create 2 diskgroups for online redo, separate from DATA, and separate from each other. This way, we don't need to be concerned with DATA transactions impacting REDO performance, and vice versa, and we still maintain redo redundancy.
In my opinion, you can't be too paranoid. :)
Good luck!
K

Location of Redo log and control files?

Dear all,
I am checking the location of redo log and control files, but found that the redo log file (like log02a.dbf ....) in the same directory of data files. However, I couldn't find any control files in the data files directries.
What could be the location of control files?
Amy

select name
from v$controlfile
or
show parameter control_filesKhurram

Non-multiplexed online redo log file damaged

how to fix if non-multiplexed online redo log file damaged , looking for info for both current & inactive..

If you only want to practice your skills these are good scenarios to do it. But if you are currently facing this problem then you are in big troubles if it happens to be the CURRENT. When this issue appears I suggest you not to shutdown the instance you should be aware that information written on the redo log is the backup of the running transactions in memory. If both get lost data is lost, if either one survives your chances to recover data are high.
~ Madrid
http://hrivera99.blogspot.com

Very high log file sequential read and control file sequential read waits?

I have a 10.2.0.4 database and have 5 streams capture processes running to replicate data to another database. However I am seeing very high
log file sequential read and control file sequential read by the capture procesess. This is causing slowness in the database as the databass is wasting so much time on these wait events. From AWR report
Elapsed: 20.12 (mins)
DB Time: 67.04 (mins)
and From top 5 wait events
Event Waits Time(s) Avg Wait(ms) % Total Call Time Wait Class
CPU time 1,712 42.6
log file sequential read 99,909 683 7 17.0 System I/O
log file sync 49,702 426 9 10.6 Commit
control file sequential read262,625 384 1 9.6 System I/O
db file sequential read 41,528 378 9 9.4 User I/O
Oracle support hasn't been of much help, other than wasting my 10 days and telling me to try this and try that.
Do you have streams running in your environment, are you experiencing this wait. Have you done anything to resolve these waits..
Thanks

Welcome to the forums.
There is insufficient information in what you have posted to know that your analysis of the situation is correct or anything about your Streams environment.
We don't know what you are replicating. Not size, not volume, not type of capture, not rules, etc.
We don't know the distance over which it is being replicated ... 10 ft. or 10 light years.
We don't have any AWR or ASH data to look at.
etc. etc. etc. If this is what you provided Oracle Support it is no wonder they were unable to help you.
To diagnose this problem, if one exists, requires someone on-site or with a very substantial body of data which you have not provided. The first step is to fill in the answers to all of the obvious first level questions. Then we will likely come back with a second level of questioning.
But when you do ... do not post here. Your questions are not "Database General" they are specific to Streams and there is a Streams forum specifically for them.
Thank you.

Where is the location of tablespace file and control file

Hi, all
where is the location of tablespace file and control file? tks

For DataFiles, query DBA_DATA_FILES or V$DATAFILE
For TempFiles, query DBA_TEMP_FILES or V$TEMPFILE
For Online Redo Logs, query v$LOGFILE
For Archived Redo Logs, query v$ARCHIVED_LOG
for Controlfiles, query v$CONTROLFILE
Hemant K Chitale
http://hemantoracledba.blogspot.com

Database restore without temp, undo and control files.

Hi All,
You might found this question silly but I don't know so asking this question here.
I have cold back up of the database. Now, I want create clone of that database, but I have some different paths for the DBFs so I will create new control file after restoring the database.
Now, I know that I don't need control files and tempfiles to be restored. I have 10 undo files in backup but on the new clone database I don't need all 10. I want only 5. So can I do the restoration without undo , temp and control file and later on add undo and temp?? and if yes then tell me that can I add them at mount level??
This is my first restore, Please guide me its very urgent

Nitin Joshi wrote:
f the COLD Backup does not include the Online Redo Logs, an ALTER DATABASE OPEN RESETLOGS is requireed >>to create these Online Redo Logs. Unfortunately, an OPEN RESETLOGS can only be done after an Incomplete >>Recovery or when using a Backup Control file.
Therefore, we do a RECOVER with a CANCEL to simulate an Incomplete Recovery.Completely agree with you Hemant. And the links you've provided,i've gone through many times. Excellent description.
I just wanted to know in above(OP's) scenario if he has complete cold backup(includes online redo logs), does he really need open reset logs or any recovery?
Regards!no , if you have cold backup with online redo log files then i don't think so you need to open database in resetlogs.Resetlog is always after incomplete recovery or recovery using backup controlfile or you dont have redo logs.
I am completely agree with you that with given scenario for the cold backup undo tablespace would not be part of recovery and you can
-offline drop undo tablespace file
-create another one undo tablespace and its undo datafile
-point spfile to that newly undo tablespace
I think Aman is saying in the context of restore and recover online database where undo tablespace create a vital role in database recovery, the undo blocks roll back the effects of uncommitted transactions previously applied by the rolling forward phase.
Khurram

How to create parameter and control file like filename + date

Hello there
I am trying to create parameter and control file with following command
in SQLPLUS
create pfile='/u03/oradata/WEBDB/backup/initWEBDB.ora' from spfile;
In RMAN
copy current controlfile to '/u03/oradata/WEBDB/backup/cf_longterm.cpy';
how can I put date at the end of filename like
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Thanks in advance
Lionel

ASM is reliable but a smart DBA is very careful. If ASM is doing mirroring this is like RAID doing mirroring. What happens if you accidentally delete one copy ... the other one disappears instantly. Not a good idea.
With respect to redo logs you need a minimum of three groups, two members, and one thread per instance. So a 2 node cluster should, at a minimum have 12 physical files.
Not mirroring the redo logs, assuming multiple members, is not as critical.

How to create redlog and control file at ASM in linux RAC

Hi Experts,
I will to maintance a oracle 10g database at ASM as RAC iin linux red hat.
i am a new person with some question.
nornally speaking, oracle recommadition for oracle 10g database as
create 3 copy fills for control file
create at least 2 redo log with mirror files in system.
However, I checked find
redlog file is at FRA place +FLSdisk1 and no mirror
control file is at FRA place--+FLSDISK1/
datebase file at ‘+DATA1/
There are no mirror for relog.
Go to EM, I also could not find place to enter file name.
We use ASM to hold database to support RAC.
Do i need to create redlog file as
ALTER DATABASE ADD LOGFILE GROUP 1 ('+FLSdisk1/sale/onlinelog/REDO01.LOG','+FLSdisk1/sale/onlinelog/REDO01_mirror.LOG') SIZE 1000M reuse;
my boss told me that ASM is reliable.
Do you need to creat more directory to arrange redlog and control files in ASM for RAC system?
FRA is a good place to store control file and redlog file ?
Thanks
JIM
Edited by: user589812 on Jul 3, 2009 3:03 PM

ASM is reliable but a smart DBA is very careful. If ASM is doing mirroring this is like RAID doing mirroring. What happens if you accidentally delete one copy ... the other one disappears instantly. Not a good idea.
With respect to redo logs you need a minimum of three groups, two members, and one thread per instance. So a 2 node cluster should, at a minimum have 12 physical files.
Not mirroring the redo logs, assuming multiple members, is not as critical.

SQL Loader and control file changes for different users

In the front end of my application I can select a data file and a control file, and load data to the table mentioned in .ctl file. Every user who logs in uses the same .ctl file and so loads onto the same table. Now I want the user to load data onto the table in his own schema. I can get the username of the user currently logged in and i want to insert it into that username.table. So can i copy the contents of the .ctl file into a variable, modify it into username.table in that string and pass that variable as a parameter to the sqlldr command instead of the .ctl file.
Or is there a better way how I can modify the same control file everytime to change tablename to username.tablename in .ctl file and pass to sqlldr to load data to table in local user schema table.
Thanks and Regards

Thanks for the reply .. user do have their user credentials but only for the application ... but all users use a common loader and control file once they log into the application. So irrespective of which user is logged in he selects the same control file and loads to the same table mentioned in the control file .. i instead want user to be able to load to the table in control file but into his schema like username.tablename instead of just the tablename mentioned in .ctl file.

After upgrading to Mavericks, all of my contacts disappeared. Did a "contacts archive" export and the file is 17mbs. Looks like there's data, but none of it at all displays. What gives? 20" iMac, early '09

After upgrading to Mavericks, all of my contacts disappeared. Did a "contacts archive" export and the file is 17mbs. Looks like there's data, but none of it at all displays. What gives? 20" iMac, early '09

After upgrading to Mavericks, all of my contacts disappeared. Did a "contacts archive" export and the file is 17mbs. Looks like there's data, but none of it at all displays. What gives? 20" iMac, early '09

Oracle binary and control files

Hi All,
I want know whether the oracle binary and control files are they related in anyway.
I have my physical files on a SAN storage and my oracle binary files on a local disk.
In case if I delete my oracle binaries and restore it from a backup, will I be able to start my database without any issues.
Since all my oracle datafiles,controlfiles and redofiles are located in SAN storage.

Oracle binaries and control files are related in some way because Oracle version is recorded in control files:
oerr ora 201
00201, 00000, "control file version %s incompatible with ORACLE version %s"
// *Cause: The control file was created by incompatible software.
// *Action: Either restart with a compatible software release or use
// CREATE CONTROLFILE to create a new control file that is
// compatible with this release.When restoring Oracle binaries on UNIX you should take care about setuid bits on oracle executable to avoid local connection issues by non oracle Unix accounts.

Load data with SQL Loader link field between CSV file and Control File

Hi all,
in a SQL Loader control file, how do you specify link with field in CSV file and Control file?
E.g. if I wat to import the record in table TEST (col1, col2, col3) with data in csv file BUT in different position. How to do this?
FILE CSV (with variable position):
test1;prova;pippo;Ferrari;
xx;yy;hello;by;
In the table TEST i want that col1 = 'prova' (xx),
col2 = 'Ferrari' (yy)
col3 = default N
the others data in CSV file are ignored.
so:
load data
infile 'TEST.CSV'
into table TEST
fields terminated by ';'
col1 ?????,
col2 ?????,
col3 CONSTANT "N"
Thanks,
Attilio

With '?' mark i mean " How i can link this COL1 with column in csv file ? "
Attilio

Multiplex Redo Logs and Control File

I am wanting to setup an existing Oracle Express 10g instance to multiplex the redo log files and the control file.
Instance is using Oracle-Managed Files and the Flash Recovery Area.
With these options being used what are the steps required to setup multiplexing?
I tried setting the DB_CREATE_ONLINE_LOG_DEST_1 and DB_CREATE_ONLINE_LOG_DEST_2 parameters but this doesn't appear to have worked (I even bounced the db instance).
BTW, the DB_CREATE_FILE_DEST is set to null and the DB_RECOVERY_FILE_DEST is set to the flash recovery area.
Any help is much appreciated.
Regards, Sheila

Thanks for this. My instance originally had two log groups so I've added a new member to each group into the same flash recovery area directory, but have assigned a name. Is this why when I query v$logfile the is_recovery_dest_file is set to NO? Is it ok to assign a name & directory and if not, how do you add a new memeber and allow Oracle-Managed files to name them?
Also, how can I check that the multiplexing is working (ie the database is writing to both sets of files)?
Thanks again.

Database in log archive mode and redo log file in mode not archive

Hello,
I have a dabatabase running in archive log mode, recently changed, I have 5 redo log groups and one of them (the current one) shows in the v$log view, that ARC: NO, I mean, no archiving. All redo logs except it shows ARC:Yes
What does it mean?
Am I going to have problems with this redo log file?
Thanks

If you do describe on v$log, you'll find that the full column name is Archived (meaning is it archived yet?).
You could try alter system switch logfile and then check v$log again a few times after.
Use the docu for finding out more about v$ views and so on
http://www.oracle.com/pls/db102/print_hit_summary?search_string=v%24log

Multiplexing Online redo logs, archive logs, and control files.

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