| Understanding FRA Files [message #505770] |
Wed, 04 May 2011 16:23  |
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eclipsis
Messages: 14
Registered: May 2011
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Junior Member |
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Hello,
I have been experimenting with RMAN over the past few days and have a fairly strong grasp on it. I setup a test scenario using a three tier incremental approach as follows:
- Every four weeks take level 0
- Every 7 days take level 1
- Every day take level 2
Obviously I'm only taking one per day, so on days I take a level 0, I'm not taking a level 1 or 2.
My scripts look similar to the following, with change to incremental level number.
rman target / <<EOF
run {
configure device type disk parallelism 4 backup type to compressed backupset;
configure default device type to disk;
configure backup optimization off;
configure controlfile autobackup on;
configure retention policy to recovery window of 4 days;
backup incremental level 0 database plus archivelog delete input;
crosscheck backup;
crosscheck backup of archivelog all;
crosscheck backup of spfile;
crosscheck backup of controlfile;
delete noprompt obsolete;
}
exit;
EOF
What I'm trying to understand is what files Oracle is creating in the flash recovery area. I have several sets of files:
In the root level of the FRA, I see several files per incremental backup with names such as aambg4sa_1_1, aqmbg5mj_1_1, b6mbg614_1_1, etc. I was under the impression that these were the incremental backup pieces, multiple files because I'm using parallelism of 4.
Under a /FRA/<SID> I see 3 directories: archivelog, autobackup, and backupset. I assume arhivelog is where Oracle is archiving the redo logs, autobackup is storing the SPFILE and CONTROLFILE as I have enabled controlfile autobackup. However, what is being stored in backupset?
When I do a crosscheck, it lists the files within backupset, but does not list the several files under the root of FRA (b6mbg614_1_1 and so on).
What's the difference between /FRA/<SID>/backupset and the files under root FRA? Do I need both for recovery - and if not, why is Oracle keeping both?
I appreciate any help.
--Thanks!
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| Re: Understanding FRA Files [message #506072 is a reply to message #505770] |
Fri, 06 May 2011 07:13  |
John Watson
Messages: 8962
Registered: January 2010
Location: Global Village
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Senior Member |
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Quote:Every four weeks take level 0
Every 7 days take level 1
Every day take level 2
Hi - one point you need to be aware of is that in 10g (according to the docs) there is no such thing as a level 2 incremental: you have only level 0, level 1, and level 1 cumulative. Specifying other levels does not throw an error, but I think this is for backward compatibility with 9i scripts. I could be wrong, but I believe you always get a level 1.
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| Re: Understanding FRA Files [message #506122 is a reply to message #506121] |
Fri, 06 May 2011 10:09 |
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eclipsis
Messages: 14
Registered: May 2011
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Junior Member |
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This was meant as more of a question. Will the block change tracking file be used for each level 1 cumulative backup - eliminating the need for a full scan of all blocks? Is it reset at each level 0?
Either way this won't impact restore/recovery? It will only speed up the level 1 backup process by reducing read/scan time.
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