Re: Oracle Databases, NTFS file systems and file system fragmentation ?

If that raid disk system is raid-5, get rid of the raid-5. Raid-5 has CRC for every write, which is a major bottleneck for all writes to redolog.
If that is 100G data on 1 single raid-array, on one disk-controller, I'm not going to tune anything: the raid-array is the source of the problem as the recommendation from Oracle and other sources, to distribute I/O amongst different individual disks are clear enough. I'm now at a shop where I have one raid-array, consisting of 3 disks, configured as a stripe set, configured as three *logical* disks, and the performance is a disaster (and of course they didn't consult us when buying that server). Also, when you loose one disk in that array, as you can't determine which file is on which disk, you basically will loose your database.
I'm not sure how much time it would take to restore 100G, but I wouldn't be prepared to live with your situation.
In my experience Oracle doesn't suffer from fragmentation at all, provided of course, you don't are continually adding new files to your database.

However, talking about application problems: did you our your firm do everything to isolate inefficient sql?
Usually it's not the hardware, but the application, and most developers just don't want to admit that.

Hth,

Sybrand Bakker, Oracle DBA

"Al Dykes" <adykes_at_panix.com> wrote in message news:8qgm19$png$1_at_panix2.panix.com...
> I'm not an oracle admin but I'm getting involved with an NT Oracle
> (8.1.5) server with application performance problems. I'd like to
> hear about possible affects of ntfs file system fragmentation and what
> production shops do about it, if/when it happens. We have about 100GB
> of data on raid disk system.
>
>
> Thanks.
>
>
>
>
> --
> Al Dykes
> -----------
> adykes_at_panix.com
>
Received on Sat Sep 23 2000 - 06:17:35 CDT