Problem in installing raw device for oracle

Dear netters,

It is said that using raw device can speed up oracle access to the database, so I formatted a patition on a disk as raw device and installed the oracle. At the beginning it works well. However, after several test tables are created, the oracle processes are terminated abnormally. When I try to restart oracle, I get the error message which says that oracle cannot access the raw device. The "format" utility shows me that the drive type became unknown:

AVAILABLE DISK SELECTIONS:

        0. sd0 at esp0 slave 24
           sd0: <SUN0424 cyl 1151 alt 2 hd 9 sec 80>
        1. sd1 at esp0 slave 8
           sd1: <Fujitsu M2654SA cyl 2194 alt 3 hd 21 sec 87>
        2. sd3 at esp0 slave 0
           sd3: <drive type unknown>

I use one patition on sd3 as raw device. The error can be repeated. I think I have made some obvious mistakes but cannot find any hints from SunOS and Oracle manules. I am using SunOS 4.1.3 on a Sparc 10 with ORACLE RDBMS V6.0.33.1.1.

I appreciate any suggestions from more experienced netters. Thanks in advance.
My email address is appended and I will also watch the group in the following days.

Jian Zhou

+-------------------------------------------------------------------+


| Jian Zhou: Fraunhofer-Institute for Computer-Graphics             |

|            Wilhelminenstrasse 7                                   |

|            W-6100 Darmstadt                                       |

|            Germany                                                |

| email: zhou_at_igd.fhg.de                   Home:   +49/6151/312269  |


| Fax: +49/6151/155199                     Office: +49/6151/155131  |


+-------------------------------------------------------------------+