From: Jaime Ornelas <jaime@cruzio.com>
Subject: Oracle8 Backup & Recovery - slow..
Date: 1997/09/09
Message-ID: <3415D03C.C75DF80C@cruzio.com>#1/1
X-Priority: 3 (Normal)
Organization: Cruzio Community Networking Service
Reply-To: jaime@cruzio.com
Newsgroups: comp.databases.oracle.server



I've been testing Oracle8 recovery manager.
On a standalone Ultra Sparc II with 5 SCSI
channels, I cannot get more than around 5Mb/s
throughput (per disk) on both backup and recovery.

Simply using the UNIX dd utility I can get
close to 9 Mb/s, which is close to the
limit of my disk. I'm backing up from disk to
disk, both on separate SCSI channels.

I can't test tape backup right now since I would
need to buy a third-party plug-in.

Anybody have a clue what I need to do to get my
througput rates up? I tried:

1. Increasing the read rate limit using the Recovery
   Manager command.
2. Increasing the MULTI_IO_COUNT (sp?), the read ahead
   parameter.
3. The Oracle Recovery Manager Guide also suggest increasing
   another Recovery Manager specific read-ahead parameter,
   but the Server did not recognize it on start up.
4. I haven't tried increasing the SGA since I can't imagine
   Oracle using the SGA for staging sequential reads.

None of the above had any effect.

You can contact me directly for more details at
jaime@cruzio.com

Thanks