Re: Recovery using RAW devices

Using raw devices is no big deal once you get used to it. A couple of pointers:

1. If the size of the raw partition is N bytes, then when you specify data file size in , say, CREATE DATABASE or CREATE/ALTER TABLESPACE, use the size N minus 1MB. UNIX uses a portion of the beginning of raw devices to record some OS related info (the size of 1 MB came from Oracle Support -- I'd like to know the exact size required, though).
2. When you back up the file, the size you specify should be the size of the raw device, not the size of the datafile (which is 1 MB less than the former).
3. If you use home-brewed backup method, then the UNIX utility 'dd' is your best bet. ORACLE Install and Config Guide for your UNIX platform generally has tips on what dd parameters to use. If you use some commercial backup tool (I've used StorageTek's REELBackup), then the tool will take care of it.

Pei L. Ku
Principal Consultant
The RightSizing Group
San Mateo, CA Received on Sun Mar 19 1995 - 18:57:06 CET