Re: ORACLE8 NT and RAID5

RAID 5 is slow for small reads and writes. It is the most efficient for redundancy, but it can bottleneck an I/O intensive database.

The appropriate RAID level depends heavily on your application. If you have a large amount of RAM that you can dedicate to Oracle, and your database is primarily a read or query database, then it won't matter. If you need to support several small concurrent transactions, RAID 5 will produce mediochre performance.

Generally speaking, you should get a heavily cached RAID controller with the flexibility of creating containers of disks running at different RAID levels depending on your needs.

Striping (RAID 1) is good for batch reads and batch writes where large amounts of data are read or written at once. Large fast disks are good for this. Applications that that write several sequential transactions to the same tables can also benefit from striping. Large extents and large datablocks also benefit from striping.

Mirroring is the safest, but the most expensive form of redundancy. RAID 0+1 or RAID 10 is generally the fastest but the most expensive means of preserving data.

Keeping distinct tablespaces partioned onto seperated disks or containers will give the best general level of performance. The RAID level will depend on the type of access and the size of the data.

Size your application carefully before you decide on the physical layout of your disks.

If your array can support hot spares, this is also an excellent means of preserving up time under RAID 5 or RAID 0.

Other more exoctic RAID levels (e.g. 7) are slowly but surely appearing on the market, but I would avoid them for now.

Christopher Weiss
Professional Services Division
Compuware Corporation

<drfuller1_at_my-deja.com> wrote in message news:7mnmu1$k2i$1_at_nnrp1.deja.com...
> We are currently configuring a new NT server for our Oracle8 database
> and I would like to know the pros or cons of using raid5 ot if anyone
> has a better recommendation, it would be appreciated.
>
> Thanks,
> Don
>
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
Received on Fri Jul 16 1999 - 15:04:50 CDT