Wait a minute! So the database was running with db_block_buffers=0? Do you also have any of the following set: db_2k_cache_size db_4k_cache_size db_8k_cache_size db_16k_cache_size db_32k_cache_size db_cache_size db_keep_cache_size db_recycle_cache_size ? You may have an issue with conflicting parameters. I don't know if that's possible or not, but given the database was running, you changed one parameter, bounced, and it failed to start, that's the first area I'd research. -----Original Message----- From: VuCanDo [mailto:vuquyen@xxxxxxxxx] Sent: Wednesday, November 03, 2004 9:29 PM To: ASKDBA Subject: [askdba] DB_BLOCK_BUFFERS - HELP Hi Guys, I was increased the DB_BLOCK_BUFFERS from 0 to 4096. After shutdown and restart the database, this is what I got an errors. I need help to start up the database that run on NT Server running on Oracle 126.96.36.199 ERROR: ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist Thanks, Vu This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.