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Re: Oracle installtion guidelines [NT]

From: Paul Drake <>
Date: Wed, 05 Jul 2000 01:33:21 -0400
Message-Id: <>


If you examine Datafile I/O - you'll get a hint about how you may want to locate your various Oracle Files. Oracle 24 x 7 and Oracle 8i DBA Handbook are excellent sources.

In order to determine I/O for files other than datafiles, you'll have to examine I/O at the operating system level. This is not as simple as in *nix, but it can be done. Oracle has instructional documents on metalink to assist you in this.

As I/O throughput has several componets (latency and bandwidth), just putting files on separate drives does not necessairily increase throughput. As online redo logs are written to in an append fashion, it is best to have NO other I/O on those drives during normal operation of the database.

Leave the drives heads on the current track - don't move them by forcing them to access another file.

Seven separate drives seems to be the magic number - that way you can separate the rbs and temp datafiles on their own separate drives. Redo logs on 3 separate drives? Why?

Put the export dump location on the redo logs drive, as little is written in redo during an export at non-peak times. I would not put the archived redo log files on their own drive, which are only written to when the online redo log file is archived.

If your redo log buffer is 192 KB, the online redo log file would be written to every time 64 KB of redo is generated. If your online redo log is 1024 KB, the archived redo log file is only written to when 1024 KB of redo has been generated - 1/16th as often.

Which do you think is more likely to be a bottleneck?

Our NT development database used to have CPU usage around 20% with a poor datafile layout.
When Indexes, User, Temp and the dump file location were put on separate drives, CPU usage hit 80% (yes, the export proceeded faster). The point is - that disk I/O was not as much of a bottleneck with a good drive layout.

If you can set the sort_area_size parameter to a large value, the TEMP tablespace won't be used as often.
If you aren't processing transactions, peformance of the Rollback Segments tablespace might not be important. Of course, Your_Mileage_May_Vary based upon the queries that are run on your database.

How about putting a single system together and benchmark performance of your app based upon configuration?


"O'Neill, Sean" wrote:
> Hi Folks,
> I'm trying to come up with a set of guidelines for installation of Oracle on
> our NT servers which in turn will help determine minimum server disk qty
> requirements. OK, it's a bit of "horses for courses" I'll admit, but I'm
> looking to develop a basic template which can be bulit upon depending on DB
> size etc. So hoping that this is not covered in some documentation.... if
> it is please let me know and I'll RTFM!
> What I've come up with so far is:
> Disk Contents RAID level
> ---------- ------------------------------- ----------
> 1 NT Server s/w, Oracle software, None
> INIT.ORA files, Startup cmd files
> 2 Control file#1 1
> RB files
> Temp Files
> Online redo logs 1, 2, 3
> 3 Control file#2 1
> Data files
> On line redo logs (mirror set 1)
> 4 Control file#3 1
> Index files
> On line redo logs (mirror set 2)
> 5 Archive logs 1
> I'd appreciate feedback any feedback on above but especially re distribution
> of various file types and RAID levels.
> Also if only 4 disks available, RAID aside, which would be best disk to
> place Archive logs on. Of course if I have some serious ommissions, or
> plain stupid notions in above please let me know too ;)
Received on Wed Jul 05 2000 - 00:33:21 CDT

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