Re: 3 X 18 GB disks

From: Mike Jones <>
Date: Tue, 1 Jul 2008 19:42:04 -0600
Message-ID: <>

<> wrote in message
> Hello,
> I got some guidance earlier (TA!) about what possibilities their were
> for slicig and dicing 3 X18 GB disks on a Sun 440 development box for
> Oracle 10G. So now current plan is to put Solaris 10 and query app on
> disk1, oracle product on a 5G B slice /u01 on disk2 and data on disk3 /
> u02.
> I know the data is not secure cos nothing is mirrored, but we are
> going to run in for a month, which should produce about 18GB of data,
> before we can move to production.
> Maybe I should create another slice or two on disk3 and use them for
> logging for example, to try and add some performance - I have not yet
> installed 10G R2 and am not shooting for ASM this time round.

Such a move is likely to decrease performance. For example let's say you divide disk3 into two equally sized slices and place the data files in slice zero and the log files in slice one. For each update the system will have to seek to slice one to write the log file and then move, on average, halfway across the disk to slice zero in order to write the DB file. By doing this you're forcing the system to perform half disk seeks. Contrast this with placing them both in a single slice and you're likely, though not guaranteed, to have significantly less seeking as the files are likely to be adjacent to one another. A seek will still need to be performed but it will be smaller.

I see you're considering placing the Oracle software installation on a 5GB slice on disk2. Did you have any plans to utilize the remaining space on the drive? Unfortunately there's not a lot of optimization you can do with three disks. While I'm a novice DBA I would suggest you consider installing the Oracle software on the OS disk (disk1) and try to utilize the remaining two disks in some way to get better performance (you can even consider placing some lightly used files on the OS disk). But again, with so few disks, I wouldn't expect a lot of performance gains.

Good luck. Received on Tue Jul 01 2008 - 20:42:04 CDT

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