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Oracle database confiruation on a 12H array

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ALH
Occasional Advisor

Oracle database confiruation on a 12H array

I have a K580 with an array 12H (autoraid) with 12 18Gb HDD?s
On this array I want to create an oracle database with a total storage of 42 Gb. In this forum and on other places i have read that the best way to create the database, is to create at least two lun?s with crossed primary/alternate and put each lun in a seperate VG for better load balacing of de LV?s created in each VG.
My first question is now: Wich database files must i put in wich LV on wich VG, so that the write load balacing is almost even. The database is oracle 7.3.4

A second question marker is, that the database must run in archive mode and that once a week an full export is created. For this we want to allocate 20Gb total. My idea is to split this in 10Gb each for export and archive. Each 10Gb is a lun = vg = lv. luns has crossed access paths.
The question is now: Is this a good idea and how must i do the cross for the access path in relation to the database luns access paths.

Cees Wielink
Netherlands
5 REPLIES
Brian M. Fisher
Honored Contributor

Re: Oracle database confiruation on a 12H array

With the AutoRAID 12H a key point to remember is ALL data is going to use ALL disks. Therefore breaking the data up into many LUNs & logical volumes will not buy you any performance gain. That being said, the only way to determine which database files should be on each of the two controllers is to look at the DB and determine which files have the highest I/O.

Brian
<*(((>< er
Perception IS Reality
Andreas Voss
Honored Contributor

Re: Oracle database confiruation on a 12H array

Hi,

it's a good idea to put oracle data files on one LUN and the index files on the other LUN (attchached on different Raid-Controllers).
Also i would put the redo and archive logs on separate disks (not on the AutoRAID) to get best performance.
When you create filesystems into your LUN's have a look at the block size: filesystem and oracle should have the same block size, usually 8192.
To set the block size for the filesystem:
newfs -F vxfs -b 8192 /dev/vgXX/lvolX

Regards

Andrew
Vlastimil Havel
Occasional Visitor

Re: Oracle database confiruation on a 12H array

I've read HP recommendation which says : create 4-6 LUNs,
stripe VG across all the LUNs,
use both controllers paths as active - interchange primary and secondary links, leave enough space for RAID 1/0 - this is the most important I think, AutoRaid performes much better if it has enough space for RAID 1/0!

It's a good idea to put redos on separate disks.

Use arraydsp to gather performance statistics of an array.

Milan
EuroTel Prague
Future is bright future is storage ...
Jim Mulshine
Frequent Advisor
Solution

Re: Oracle database confiruation on a 12H array

I've got an Oracle database installed on a volume group consisting of 6 LUNs spread over 3 AutoRAIDs. The two LUNs per AutoRAID have crossed Primary/Alternate paths. While some LUNs have both tables and indexes, tables are on separate LUNs (and primary paths) and even separate AutoRAIDs (in some cases) than their own indexes. The tables/indexes were placed strategically so that each of 5 LUNs has a good mix of highly and lowly accessed data. Six redo logs are on 2 LUNS (2 different primary paths) and are placed so that redo log files 1,3,5 are on the first LUN and redo log files 2,4,6 are on the second LUN. A logical volume with a filesystem for archive log files is placed on a different LUN than the redo log files and tables/indexes. A rollback segment data file and some other filesystems (sometimes used for exports) are also located on this LUN.
Maarten van Maanen
Regular Advisor

Re: Oracle database confiruation on a 12H array

Cees,

We have an Oracle 8.0.5 database running on a 12H with six 18Gb HDD installed and with all of Oracle running on the 12H though I'm planning to change the log-files to the system-disk as soon as a know a bit more about Oracle and have some time to spare.

If you're interested, I've got a Word document which was created during the setup of our current 12H configuration (in Dutch) using both controllers for better performance. It shows exactly how we did it (and what went wrong as well of course). If you could mail me at MMaanen@computer2000.nl I could send you this file.

Regards,
Maarten van Maanen
Computer 2000
Netherlands