Deleted redo log files

hi everbody,
i use oracle 9.2 and 3 redo log files was created when installation. Now, i could not open database because two of redo log files was deleted (that i haven't understood how deleted.) So what can i do ? recovery is possible ? if poosibel how ?
NOTES :
my database does not work Archive mode and give below error messages...
Total System Global Area 126950220 bytes
Fixed Size 453452 bytes
Variable Size 96468992 bytes
Database Buffers 29360128 bytes
Redo Buffers 667648 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: 'C:\ORACLE\ORADATA\ABUZER\REDO01.LOG'

thanks everbody. i couldn't give information because some problems was internet connections. i solved problems. i found command and info in the Oracle 8i Admin Guide documentation. first i dropped two log groups whose files are missing then recreate these these log groups with redo log files..before that i start up an new instance, but do not mount the database. after that i use commands like below :
ALTER DATABASE DROP LOGFILE GROUP 1 ;
ALTER DATABSE DROP LOGFILE GROUP 2 ;
ALTER DATABASE ADD LOGFILE GROUP 1 ('C:\...\REDO01.LOG') SIZE 1020400K
ALTER DATABASE ADD LOGFILE GROUP 2 ('C:\...\REDO02.LOG') SIZE 1020400K
thanks everbody...

Similar Messages

Deleted redo log files in test

hi,
i was working in my test environment.
by mistake all the redo logs were deleted.(all members)
now the database is not starting.
please give sugestion as how to open the database again.
Regards

Was the DB shutdown when it was deleted?:NO
SQL> recover database until cancel;
ORA-00279: change 236004 generated at 01/04/2010 21:03:06 needed for thread 1
ORA-00289: suggestion : C:\ORACLE9\ORA92\ORADATA\ITD\ARCHIVE\1_3.DBF
ORA-00280: change 236004 for thread 1 is in sequence #3
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
CANCEL
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: 'C:\ORACLE9\ORA92\ORADATA\ITD\SYSTEM01.DBF'
ORA-01112: media recovery not started

How to clean redo log file?

Hi, guys:
I need to migrate data from external tables to normal tables. But the connection is always frozen half the way of executing script. The error message is ORA-00257. it looks redo log file is full. I tried to delete redo log file with RMAN, but I got this error message:
delete archivelog until time 'trunc(sysdate)';
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=43 device type=DISK
specification does not match any archived log in the repository
Any suggestion would be appreciated.
Sam

lxiscas wrote:
Hi, guys:
I need to migrate data from external tables to normal tables. But the connection is always frozen half the way of executing script. The error message is ORA-00257. it looks redo log file is full. I tried to delete redo log file with RMAN, but I got this error message:
Sounds like you are confusing (online) redo logs with "archivelogs" (archived redo logs).
You don't delete redo logs at all. You can delete archivelogs with rman, which is what your command is trying to do. Do you ever backup the archivelogs? A proper backup/recovery policy would backup the archivelogs on at least a daily (if not more often) basis, and delete them after they are backed up. That will keep the archivelog destination from filling up in all but the most extreme circumstances.
delete archivelog until time 'trunc(sysdate)';
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=43 device type=DISK
specification does not match any archived log in the repository
Any suggestion would be appreciated.
Sam

Delete old and unused Archived Redo Log Files

Hello forum!
My db was in ARCHIVELOG mode and It created 9GB of archived redo log files.
Now I put the db in NOARCHIVELOG mode, can I delete all the ARLF? am I sure that the DB never need those files in the future?
If yes, how can I delete them? I will use 'del' operative system command?
In addition, I found this command:
SQL>alter database open resetlogs;
is it useful for my purpose?
thank you!

You are safe to remove those archivelog files if you altered your database to no archive log mode. Just remove them from OS level
Please bear in mind that database in no archivelog mode will lost data in the event of disaster.
SQL>alter database open resetlogs;Doesn't help in your situation, it's use to bring up database after incomplete recovery.

Accidently Deleted Online Redo Log Files

Dear friends
Just to give a try, I deleted online redo log files from the disk after clearn shutdown (In Test Environment Not A Production Database), then i started the dabase, I know we need atleast two online redo files for database to work properly. now my point of question is how can i create new online redo files ?
I have 2 redo logfile groups each with one member. In group 2 i have added new member for the deleted one using add logfile member ....... to group 2. but when i try todo the same to add logfile member to group1 I am not abale to do so. because its saying that this is the current logfile member. then I tried manual log switching to use next logfile member but database is not allowing as the database is just mounted not opened. plsease if any body helps me out to sort out this problem it will be a great help.
Anandkumar S.M
Oracle DBA
rC6Exv3

hello ur instruction u have is some what bit rite. but i was not able to solve the problem
finally i solved the problem with these commands after database is mounted
recover database until cancel Enter
then I select the cancel option when it provide the user with the options
after cancelling the recover i issued the following command
alter database open resetlogs;
this method sorted out my problem
anyway very very thanks for ur root hints from where i got the Idea to recover online redo logfiles
Thank u very much

Redo log files deleted

Hello,
One of my friend deleted redo log and control files of one machine in cluster environment. Oracle parallel server(8.1.7) is installed on this cluster.
Redo log and control files of the second disk is still there.
Can i copy the control files and redo log files of the second disk to the first one...??? Will it work ???
Please let me know how should I go by it...??
Thanking in anticipation.
Regards,
Rajeev

Hello,
I don't have any experiences with cluster/parallel server. But in general:
1. Controlfile: shutdown database and cp exisiting controlfile to "old" destination. Filename must be similar to deleted controlfile.
2. Redo Logs: Drop and recreate groups step by step (no user activity recommended). Database won't crash, because members are still "alive" on second disk.
HTH,
juergen_klinsmann

Online redo log files being removed physically

Grid Infra version: 11.2.0.4
RDBMS Version: 11.2.0.4
Although this is a RAC DB, this is not a RAC-specific question. Hence posting it here.
Few months back, I remember issuing a command similair to below (DROP LOGFILE GROUP ...) and the redo log files were still physically present in the diskgroup.
If I remember correctly, the file is not deleted physical so that we can use the REUSE functionality (ALTER DATABASE ADD LOGFILE MEMBER '+REDO/orcl/onlinelog/redo1b.log' reuse to group 11; ) ie. you can use the REUSE command to add the logfile of the same name which is physically present in OS Filesystem/Diksgroup to redo log group.
But today, after I issued the below command, I checked the diskgroup location from ASMCMD
SQL> alter database drop logfile group 31;
Database altered.
From ASMCMD, I can that the file has disappeared physically. Is this a new feature with 11.2.0.4 or am I missing something here ?
ASMCMD> ls +DATA/msblprd/onlinelog/group_31.548.833154995
ASMCMD-8002: entry 'group_31.548.833154995' does not exist in directory '+DATA/msblprd/onlinelog/'

Just to add to what Aman has said.
It is a bad practice not to let OMF decide the placement of Online redo logs because of this issue especially when you use ASM.
Executing rm command in Linux/Unix is easy but Dropping ASM aliases in the disk group can be a hassle.
This is documented.
"When a redo log member is dropped from the database, the operating system file is not deleted from disk. Rather, the control files of the associated database are updated to drop the member from the database structure. After dropping a redo log file, ensure that the drop completed successfully, and then use the appropriate operating system command to delete the dropped redo log file."
http://docs.oracle.com/cd/E11882_01/server.112/e25494/onlineredo.htm#ADMIN11324
BTW . You don't even need to set db_create_online_log_dest_n to enable OMF for ORLs.
SQL> show parameter log_dest
NAME                                 TYPE        VALUE
db_create_online_log_dest_1          string
db_create_online_log_dest_2          string
db_create_online_log_dest_3          string
db_create_online_log_dest_4          string
db_create_online_log_dest_5          string
SQL> show parameter db_create_file_dest
NAME                                 TYPE        VALUE
db_create_file_dest                  string      +MBL_DATA
alter database add logfile thread 4
group 31 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 32 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 33 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 34 ('+MBL_DATA','+MBL_FRA') size 4096M ;
Database altered.
And redo logs will be neatly placed as shown below
   INST     GROUP# MEMBER                                             STATUS           ARC
         4         31 +MBL_DATA/bsblprd/onlinelog/group_31.276.832605441 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_31.297.832605445 UNUSED           YES
                   32 +MBL_DATA/bsblprd/onlinelog/group_32.547.832605451 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_32.372.832605457 UNUSED           YES
                   33 +MBL_DATA/bsblprd/onlinelog/group_33.548.832605463 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_33.284.832605469 UNUSED           YES
                   34 +MBL_DATA/bsblprd/onlinelog/group_34.549.832605475 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_34.359.832605481 UNUSED           YES

Redo log file thread

Dear All,
In am using oracle 10.2.0.4.0 in RHEL 4.
In my current set we had two node RAC (tims1,tims2) db_name (tims).
One of the node has failed(hard disk),Failed node information has been remove from OCR(all the cluster component like...ons,vip,listener,instance).
My Question IS:After Removing All the Cluster Component does it remove redo log files associate with the failed instance.
Redo logfile Before Node Delete:
SQL> select member from v$logfile;
MEMBER
/database/tims/redo02.log
/database/tims/redo01.log
/database/tims/redo03.log
/database/tims/redo04.log
Redo Logfile After Node Delete
SQL> select member from v$logfile;
MEMBER
/database/tims/redo02.log
/database/tims/redo01.log
/database/tims/redo03.log
/database/tims/redo04.log
It means redo logfile has not been removed.
Please help me what are the redo thread i will have to remove.
SQL> select group#,sequence#,thread# from v$log;
    GROUP# SEQUENCE#    THREAD#
         1      28868          1
         2      28867          1
         3      29327          2
         4      29328          2
Thanks &Regards
Monoj Das

monoj wrote:
Dear All
SQL> select group#,sequence#,thread# from v$log;
    GROUP# SEQUENCE#    THREAD#
         1      28868          1
         2      28867          1
         3      29327          2
         4      29328          2
According to my above query, thread# for group 1,2 is showing as 1 but the thread has been remove from cluster is there any use of those redo log.
Thanks and Regards
Monoj Das
Please leave your theories aside and read the replies given in the thread. The logs are going to stay as they are (should be) on the shared storage. Why you are hard-bent to remove these log files anyways? Are you not willing to add the other instance? RAC db with just one instance is really not of much use.
Aman....

Removing Redo Log Files? What's Normal?

Hello,
I'm new to Oracle and I've been using Informix for years. We currently have Oracle 9.2 running on Windows 2000 Server machine and apparently the redo log files keep filling up the disk drives they reside on. This is happening about every two weeks since we go out and delete the files when we remember.
My question is does Oracle have a "normal" way of removing old redo logs automatically rather than having to remove them manually? In the Informix world I can set the logical logs so that they write over previously used logs once they are no longer used. Is there a similar way to configure Oracle?
Thanks for helping out.
Gregg Walker

Do not delete your old log files: you need them.
That's how Oracle does recovery when you lose a datafile or a drive. You copy over the missing stuff from your back-up and then Oracle re-applies the chnages from the REDO logs thereby bringing your database back up to date. No work lost. Result!
Of course, if you don't take up a backup then holding on to REDO logs is pointless. In which case, set the database to run in NOARCHIVELOG mode.
However, I strongly advise you to run in ARCHIVELOG mode. You may find this part of the administrator's guide informative: http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/archredo.htm#4553
Cheers, APC

Commit Completes although current online redo log file have been removed.

Although i have removed current online redo log file in linux os (Oracle Linux),when i type "commit" it says that "commit complete".
Is this fair for this princip?*:" if Only when all redo records associated with a given transaction are safely on disk in the online logs is the user process notified that the transaction has been committed."*
I think that it can lead to loss of data in some cases..I'm using Oracle 11g R2 on OEL (x64)..
Can anyone explain me ? I'm getting stuck in this situation..
P.S : I haven't multiplexed current ORL group files...

Javid wrote:
Although i have removed current online redo log file in linux os (Oracle Linux),when i type "commit" it says that "commit complete".
Is this fair for this princip?*:" if Only when all redo records associated with a given transaction are safely on disk in the online logs is the user process notified that the transaction has been committed."*
I think that it can lead to loss of data in some cases..I'm using Oracle 11g R2 on OEL (x64)..
Can anyone explain me ? I'm getting stuck in this situation..
In *nix, a file that is open by a process isn't really deleted until the process that has it completes. So even though you 'deleted' a redo log, oracle is still holding it. As soon as you stop your database (maybe even as soon as the db does a log switch) the redo will really be gone and no longer available. consider the implications for archive logging.
P.S : I haven't multiplexed current ORL group files...You need to fix that. the online logs are the achilles heel of the database. That's why it is standard practice to multiplex them.

Manual delete archived log files

Because we don't have RMAN in our development server, I need to use manual operation to delete all archived logs. Is my procedure correct and safe?
SHUTDOWN IMMEDIATE
STARTUP MOUNT
ALTER DATABASE NOARCHIVELOG;
EXITRun OS command to manually delete archived log files:
rm /oradata/arch/*
Login to sqlplus
SHUTDOWN IMMEDIATE
STARTUP MOUNT
ALTER DATABASE ARCHIVELOG;
STARTUP OPENThanks!

linuxos wrote:
Oh I suppose RMAN need to be configured somthing before use. I tried it, and find no pre-requisite is required. Thanks!
If the archives are deleted manually in open mode, how can Oracle match the archived logs' retention policy? Does Oracle store the archived logs in data dictionary?While you can delete archivelogs manually any time you want, you should let rman manage them with appropriate rman commands, preferably in a script that you schedule for regular execution.
Some of your questions lead me to question if you understand that archivelogs are not actively open by the database, and they technically are not part of the database. They are simply a series of "offline" copies of the online redo logs. They are written to once, when an online redo is being archived, then they just sit there until needed for a recovery.

What is online redo log files???

Dear All,
I m bit confused with redo log files.what is need of back up of redo log files?????As i m new in the Basis please tell me i always get confused with redo log files and archive files.
Thanx and reagard's
Ashok

In Oracle you have a number of online redo log files.
In an typical SAP installation you have two directories:
origlogA and origlogB
origlogA contains online redo log 1 and 3 and
origlogB contains online redo log 2 and 4.
In most installation you also have mirrlogA and mirrlogB, which the name tells, is mirrors of origlogA and origlogB.
Now, the online redo logs are circular,
so when 1 gets full oracle jumps to number 2.
At the same time oracle's archiver process starts to copy
online redo log number 1 to a file on disk.
This files are also known as archive redo logs.
In an recovery situation you might do with just the online redo logs,
but usually a combination of both online and archive redo logs is needed.
During database backup, you also backup the online redo logs
You also need to backup (backup twice then delete) archive redo logs.
the archive redo logs are your way back from the restored database to the last transaction of the database.
If one archive redo log is missing, you have to stop you recovery there and loose the rest of the transactions done in the database.

Multiplexing Redo Log Files question

If you are running RAC on ASM on a RAID system, is this required? We are using an HP autoraid which mirrors at the block level and in the documentation about Multiplexing Redo Log Files it says that you do it to protect against media failure. The autoraid that we are using gives us multiple levels of redundancy against media failure so I was wondering if Multiplexing would be adding more overhead than is needed. Thanks for your input.

ASM is quite compex and I'm not going to outline all the advantages or reasons for ASM, but under ASM you can drop and add devices to maintain your capacity needs online without loosing data, which you cannot do using RAID, which requires a re-initialize, for example, regardless of redundancy. Please see the documentation. ASM, like pretty much everything Oracle will add complexity and you will have to check your requirements. ASM is however pretty much the standard. If you use external RAID, make sure your storage is not using RAID 5 or 0. Regarding logical errors, you could for example overwrite or delete a file by mistake, in which case file redundancy does not protect you. If you are looking for reasons or ways not to use ASM, I'm sure you will find them, but what's the point?

Redo log file corupted, database not getting open

I am Oracle Funda-1 student.
Have install standard Oracle 9I on Windows XP pro service pack 2.
I made some changes in sample table & given commit. So log buffer will flush to redo log file.
Then I open current redo log file from OS & selected all junk characters [select all] & deleted same. Save the file. Causing redo file size 0KB.
Then made more changes to table & issue commit. no errors ! every thing working file.
Even chked V$log & V$logfile.
Again I open current redo log file from OS & selected all junk characters [ select all ] & deleted same. Save the file. Causing redo file size 0KB.
Then issue manual log switch. Alter system switch logfile
I got disconnected from database & database was close.
When I reconnected & try to open database in normal mode. Gave error saying redolog_1.log is corrupted & needed for recovery.
Now not even allowing me clear redo group 1. with alter database clear logfile group 1. as database is not coming to open stage.
just able to mount the database. with error rdolog_1 corrupted.
Wasn't oracle suppose to be halted when very 1st time I corrupted redo log file.
Why it disconnected me & got close.
When then one use alter database clear logfile group 1.

I may try this ALTER DATABASE OPEN RESETLOGS;
As no backup & not multiplex.
Still looking for explanation why database got close down instead of getting halt.
I have found one more status in V$log, which is not given in Oracle university book or online document.
INVALIDATED
Which come as a result when oracle unable to switch to next on line group due to non availability of next group redo log physical file.
SQL> select group#,members,status from V$log;
GROUP# MEMBERS STATUS
1 1 INVALIDATED
2 1 INACTIVE
4 1 UNUSED
As matter of fact, it's only portion of a big
document which happen to cover what you are testing
in detail.
I would invest time to read the document to
understand how things work instead of getting dirty
quick answers.

Question about how Oracle manages Redo Log Files

Good morning,
Assuming a configuration that consists of 2 redo log groups (Group A and B), each group consisting of 2 disks (Disks A1 & A2 for Group A and Disks B1 and B2 for group B). Further, let's assume that each redo log file resides by itself in a disk storage device and that the device is dedicated to it. Therefore in the above scenario, there are 4 disks, one for each redo log file and, each disk contains nothing else other than a redo log file. Furthermore, let's assume that the database is in ARCHIVELOG mode and that the archive files are stored on yet another different set of devices.
sort of graphically:
    GROUP A             GROUP B
      A1                  B1
      A2                  B2The question is: When the disks that comprise Group A are filled and Oracle switches to the disks in Group B, can the disks in Group A be taken offline, maybe even physically removed from the system if necessary, without affecting the proper operation of the database ? Can the Archiver process be temporarily delayed until the disks (that were removed) are brought back online or is the DBA forced to wait until the Archiver process has finished creating a copy of the redo log file into the archive ?
Thank you for your help,
John.

Hello,
Dropping Log Groups
To drop an online redo log group, you must have the ALTER DATABASE system privilege. Before dropping an online redo log group, consider the following restrictions and precautions:
* An instance requires at least two groups of online redo log files, regardless of the number of members in the groups. (A group is one or more members.)
* You can drop an online redo log group only if it is inactive. If you need to drop the current group, first force a log switch to occur.
* Make sure an online redo log group is archived (if archiving is enabled) before dropping it. To see whether this has happened, use the V$LOG view.
SELECT GROUP#, ARCHIVED, STATUS FROM V$LOG;
GROUP# ARC STATUS
1 YES ACTIVE
2 NO CURRENT
3 YES INACTIVE
4 YES INACTIVE
Drop an online redo log group with the SQL statement ALTER DATABASE with the DROP LOGFILE clause.
The following statement drops redo log group number 3:
ALTER DATABASE DROP LOGFILE GROUP 3;
When an online redo log group is dropped from the database, and you are not using the Oracle Managed Files feature, the operating system files are not deleted from disk. Rather, the control files of the associated database are updated to drop the members of the group from the database structure. After dropping an online redo log group, make sure that the drop completed successfully, and then use the appropriate operating system command to delete the dropped online redo log files.
When using Oracle-managed files, the cleanup of operating systems files is done automatically for you.
Your Database wont be affected as you can operate with 2 redo log files in each group as The minimum number of redo log files required in a database is two because the LGWR (log writer) process writes to the redo log files in a circular manner. so the process will hang becuase you are having 2 only groups if you want to remove 1 add a third one and make it the current group then remove the one you want to be offline.
Please refer to:
http://download.oracle.com/docs/cd/B10500_01/server.920/a96521/onlineredo.htm#7438
Kind regards
Mohamed
Oracle DBA

Deleted redo log files

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