- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - HP-UX
- >
- Re: Oracle archivelog mode !!
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-15-2003 07:53 PM
тАО01-15-2003 07:53 PM
Is it possible to recovery the system from archive logs if we only have:
1. export backup image
2. offline database backup
3. online database backup
Please help evaluate the possiblity and steps (if any) in the above 3 options.
Many thanks,
Chris
Solved! Go to Solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-15-2003 08:07 PM
тАО01-15-2003 08:07 PM
Re: Oracle archivelog mode !!
2. Yes. Be careful not to open the database after mounting, as you will not be able to recover the database. Once the datafiles have been restored, put the database into a mount state and apply the logs to the database.
3. Yes. You will have to have all of the logs generated to the last tablespace "end backup" command.
Brian
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-15-2003 10:06 PM
тАО01-15-2003 10:06 PM
Re: Oracle archivelog mode !!
1. No, you can't recover from export backup image to the point of DB crash when it is in archive log mode.
2. It's possible provided if you have backup of log/data/control files backup till the point of DB crash.
3.Yes, If you have log files backup till the point of DB crash
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-16-2003 12:22 AM
тАО01-16-2003 12:22 AM
SolutionA few comments.
Export:
=======
First of all, today, where 24x7 is a requirement, EXP and IMP are not backup and recovery tool at all. They are relatively simple tools that should be used to move a modest amount of data back and forth between instances, or, by using transportable tablespaces, to move massive amounts of data. To use it to backup a 500GB database would be ludicrous.
Offline backup:
===============
Copying of the datafiles, control file and online redo log files must be done by using an operating system copy utility. This is a considered as a complete backup of the database. Any changes made after this backup will be unrecoverable if the database is running in NOARCHIVELOG mode. All transactions are recorded in online redo log files whether archiving or not. When redo logs are archived (ARCHIVELOG mode), ORACLE allows you to apply these transactions after restoring files that were damaged (assuming an active Redo log file was not among the files damaged).
Online backup:
==============
A database backup, together with online and archived redo log files, guarantees that you can recover all committed transactions in the event of an operating system or disk failure.
You can use a backup taken while the database is open and in normal system use if you keep an archived log.
At sites where a database must operate 24-hours per day and when it is not feasible to take offline backups, then an alternative is provided by Oracle where physical backups are performed while the database remains available for both reading and updating. For this kind of backup the database must be in ARCHIVELOG mode. Only data files and current control file need to be backed up. Unlike offline backups, the unit of a online backup is a tablespace, and any or all tablespaces can backed up whenever needed. Different datafiles can be backed up at different times.
In general for Media Recovery using archived log, the following applies:
Manual recovery after media failure enables you to control how many redo log files to apply to the database. This can used to undo an inadvertent change to the database by stopping recovery before the change took place. MANUAL option needed for recovery with a control file backup (old copy) and current control file is not available. Database must be MOUNTed but not OPEN. After MOUNTing the database connect internal and issue RECOVER DATABASE MANUAL command. Then you will be prompted beginning with the earliest redo log file recorded in the header of each database file. The recovery process will continue to prompt for redo log files until CANCEL is typed when prompted for the next redo log file. Recovery can be cancelled at any time of any redo log.
How to apply ARCHIVED LOGS on an OFFLINE BACKUP
-----------------------------------------------
Datafiles should have information of log change nbr (SCN), so Oracle knows which archived logs need to be applied to get DB on date. This can be done "usually":
- alter database mount
- recover database until cancel
- alter database open [resetlogs] (if uncomplete recovery)
If you need any further clarifications please let us know.
Hope this helps!
Best Regards
Yogeeraj
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-16-2003 10:14 PM
тАО01-16-2003 10:14 PM
Re: Oracle archivelog mode !!
Thanks for all your inputs especially for "Yogeeraj". Very much help !!
It seems online database backup is the only choice for a 24x7 database......however, what about for "Data warehouse"....during the day time, it has to sever the users and at night it has to perform the data loading processing......!! Turning on archivelog mode will greatly impact the data loading process...!!
We also can't afford not to perform backup on the data warehouse.....any suggestions other than using database export ?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-16-2003 10:48 PM
тАО01-16-2003 10:48 PM
Re: Oracle archivelog mode !!
Other wise you can archive the read-only data i.e the earlier years data and configure the script that runs the hot backup (on-line) backups to backup only the current data that is beeing loaded.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-16-2003 11:10 PM
тАО01-16-2003 11:10 PM
Re: Oracle archivelog mode !!
Another option is to use rman. While this will not reduce the I/O, it does not require the database to be put in a "backup state" that generates additional redolog information.
Brian
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-17-2003 08:21 PM
тАО01-17-2003 08:21 PM
Re: Oracle archivelog mode !!
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-19-2003 12:38 AM
тАО01-19-2003 12:38 AM
Re: Oracle archivelog mode !!
rman can take pretty nice hot backups, but we have the luxury of taking ours cold.
I'm bookmarking this post and will try and get my dba to comment.
As someone with a few oracle recoveries under my belt, you got great help here. As you've already noted.
The only thing we use export/import for is migrating data between platforms or db versions.
Steve
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-07-2003 08:53 PM
тАО05-07-2003 08:53 PM
Re: Oracle archivelog mode !!
When I use rman to restore backuped archivelog , I get such error:
RMAN-06026: some targets not found - aborting restore
RMAN-06025: no backup of log thread 1 seq 1697 scn 57340 found to restore
RMAN-06025: no backup of log thread 1 seq 1696 scn 57309 found to restore
can you help me?