Optimal Flexible Architecture - eliminates fragmentation ?
Yakgna, March 09, 2003 - 12:02 pm UTC
from the link....
OFA is designed to:
.
.
.
.
.Help eliminate fragmentation of free space in the data dictionary, isolate other fragmentation, and minimize resource contention
-this is the one in which i am interested to ask/know. how is that??
...Thanks
March 09, 2003 - 12:09 pm UTC
good question, do you have a direct url to those rather mysterious comments. out of context, I cannot say.
that link points to many documents -- please be a tad more specific as to what I'm to look at.
here's that link...
Yakgna, March 09, 2003 - 12:18 pm UTC
March 09, 2003 - 12:30 pm UTC
if you read on down, they mention:
Separation of Tablespace Contents
Tablespace contents are separated to:
* Minimize tablespace free space fragmentation
* Minimize I/O request contention
* Maximize administrative flexibility
meaning they start by putting things in separate tablespaces by how they are used.
In this day and age of LMTs -- it is fairly meaningless to talk of free space fragmentation anymore. mostly applies to people who are using the old way (DMT's) and only applies to the initial setup of the DB
You are free to totally mess it up after the install ;)
A reader, February 16, 2006 - 2:38 am UTC
For a system that uses a logical volume manager or ASM, is OFA standard still useful in terms of reducing I/O contentions?
Speaking of ASM, is it generally used independent of a logical volume manager or is it used togethre?
February 16, 2006 - 11:44 am UTC
OFA wasn't so much about IO reduction as it was "everything has a place, and everything should be put into its place so anyone can sit down and immediately know where everything is"
so yes, OFA can still be very useful - for consistency sake.
ASM is a logical volume manager (LVM) in a manner of speaking :)
</code>
http://asktom.oracle.com/Misc/so-what-was-answer-part-iii.html <code>
you use it instead of some other LVM
How to move admin directory
Tom, September 04, 2006 - 1:24 pm UTC
Tom,
I really like the consistency offered by OFA, however I don't like putting the admin directory in the same directory as the software. I would prefer to have c:\oracle containing the oracle software and c:\database [or d:\database etc] containing all files related to my database - data, backups, exports, admin etc.
Questions.....
1. How do I move the admin directory for an existing database....I can set user_dump_dest,etc for udump,bdump and cdump but what about "create" and "pfile"? Are these just legacy from the database creation?
2. Using DBCA how do I change the admin directory when creating the database....is it just a case of setting the dump, bdump and cdump parameters?
September 04, 2006 - 2:32 pm UTC
1) for the dumps, just change the init.ora
for the pfile (create is nothing, not used after - well - the create), you should be using an spfile and those are in the dbs or database directory, not under admin (just be careful that the dbs/database ones are not pfiles with a single ifile= in them! if so, you'll need to change that)
2) yah, pretty much.
How about moving the spfile - not a good idea
Tom, September 05, 2006 - 4:56 am UTC
Hi Tom,
Thanks for the response. I figured the create directory wasn't important and I am using an SPFILE. A couple more questions though...
1. My intention was to move all files related to a single instance [data,configuration,trace files] out of the oracle software directory to keep a nice clean separation between the oracle software and the database itself. Do you see this as a good idea?
2. Since I am using an SPFILE it defaults to the \database directory. Can I change this default location for the spfile and are there any "gotchas" to watch out for if we do?
Out of interest, how do you lay out the files for the asktom instance?
September 05, 2006 - 5:03 pm UTC
1) no, dbs or database will be the default, you will want to keep that.
2) spfile OR pfile does this. You would have to either explictly state where it is when you startup OR put behind dummy ones that point to where they are.
I would not recommend this.
we have rdbms/admin files on another mount point (traces and such) but parameter files are all on the $ORACLE_HOME/dbs
ORA-12705: Invalid or Unknown NLS parameter
Satesh Kumar, September 05, 2006 - 1:13 pm UTC
Hi Tom,
I need your help in solving this problem I am able to connect to SQL PLUS but I am not able to connect to neither TOAD or PLSQL DEVELOPER .I changed the registry setting NLS_LANG but still unable to connect I am getting the same message ORA-12705: Invalid or unknown NLS parameter value specified.I really appreciate that.Thanks
September 05, 2006 - 5:27 pm UTC
sounds like different oracle homes being used.
I don't really know the layout of your machine, the client libraries thusly required.
more on OFA
George, November 09, 2006 - 1:53 pm UTC
Tom,
I am installing a new server today, and several over the next few months. Everything I've read says I need two mount points - one for software, one for data. Clearly it makes sense to install to separate directories, but the
whole disk is RAID5 and logically 1 disk to the OS anyway.. it seems to me the benefit is in favor of a single mount point so I can manage just 1 space concern going forward.
Is there really any benefit to /u01 and /u02 rather than just /u01/app and /u01/oradata ?
Also, I have the option of adding a mount point (or more) on the SAN. We have several instances where we have installed databases on the SAN and it has caused considerable iowait issues. Thus my current thinking is to keep 1 control file on the SAN, and I am debating whether to locate archive or redo logs there.. really I think that would be a performance hit, but perhaps justified from a recovery perspective. What do you think?
Thanks, George
November 09, 2006 - 2:41 pm UTC
is there really any benefit? nothing comes to mind no.
I think I'd be trying to figure out the root cause, because to say "SAN is slow" is not a good thing - they are "not" in general.
Directory Structures
A reader, October 31, 2012 - 6:30 pm UTC
Tom:
I need your help in understanding the OFA and how I create my folders to comply with it.
I have a RHEL virtual machine configured as RAID 10. Machine has 8 drives and 4 drives will be used for mirroring.
Since the Virtual machine is an ESXi datastore/file it is being striped acorss 4 disks.
I requested 3 virtual disks be created for better management:
1) One virtual disk for oracle software
2) One virtual disk for two databases files
3) One virtual disk for backup files and Flash recovery
Reading this link, at the bottom it seems all files go under /u01 like database files and flash recovery and backups unless it is an empty directory and used as a pointer.
http://docs.oracle.com/cd/E11882_01/install.112/e24321/appendix_ofa.htm#sthref791 But logcally speaking, it seems i need this structure for mount points
/u01-->Virtual Disk1-->oracle software
/u02-->Virtual Disk2-->All database files
/u03-->Virtual Disk 3-->backups and flash recovery
How would you lay out the storage and directories based on the above hardware configuration and be compliant with OFA?
Thanks,
October 31, 2012 - 7:39 pm UTC
just get one big disk and use dbca to install and configure, accepting all of the defaults.
since you only have four disks and they'll all be striped with each other, using separate virtual disks would just be limiting to you, it wouldn't buy you anything.
OFA
A reader, October 31, 2012 - 9:33 pm UTC
Tom:
Virtual disks are just files for easier management or administration. I can copy or backup a file/virtual disk which has the backup files to another remote disk.
so in your opinion, I should have everything (oracle software, data files ,control files, redo logs, archive redo logs, backup files and flashback) all under the /u01 directory?
what are the /u02 and /u03 mount points used for under OFA?
October 31, 2012 - 10:23 pm UTC
you'd want to backup the VM wouldn't you sam.
I just use the out of the box install for small databases. I don't do OFA. We keep the code in one subtree, we keep the database in another.
Just DBCA it.
OFA
A reader, November 01, 2012 - 6:11 am UTC
Tom:
Good morning!
The SA will be backing up the VM.
I will only back up the database.
I thought out of the box install uses OFA.
Is not the directory structure created before DBCA when you use the OUI (oracle universal installer). DBCA creates the data files, control files ,etc into those directories.
Is your final recommendation for this local storage VM scenario: use one VM disk (not three) and install everything under /u01 directory?
November 01, 2012 - 10:18 pm UTC
Sam -
just use the dbca configuation, you'll be backing up using rman, not using 'virtual disks', the number of disks you have will not affect your backup at all. dbca does OFA out of the box - but it wouldn't be using /u01, /u02, etc etc etc.
if you use many virtual disks, I believe you'll find yourself limiting yourself. If you just use one, given you only have four real disks anyway, your life will be 'better', 'easier'.
it is totally up to you, I've given you my opinion Sam, that is all.
OFA
A reader, November 02, 2012 - 7:09 am UTC
Tom:
yes, thanks, i have requested one big disk per your opinion.
But would everything (data files, backups, archive files) be stored under /u01 tree?
Would you request one mount point for oracle or several mount points for this virtual disk?
November 05, 2012 - 8:33 am UTC
I use /home/oracle myself, but you can name it whatever you want - it is purely a matter of preference.
if you only have one big disk, Sam, by *definition* you have one mount point.