I/O Read Rate of Backups
备份IO读的速度
By default, RMAN uses all available I/O bandwidth to read/write to disk. You can
limit the I/O resources consumed by a backup job with the RATE option of the
ALLOCATE CHANNEL or CONFIGURE CHANNEL commands. The RATE option specifies
the maximum number of bytes for each second that RMAN reads on the channel.
默认的，RMAN使用所有可用的IO带宽去读和写磁盘。你可以限制IO资源的占用通过使用一个
备份任务使用allocate channel或者configure channel命令的RATE选项。RATE选项指定了每次
RMAN从通道中每秒读取的最大字节数。
For example, you can configure automatic channels to limit each channel to read
1 MB
a second:
CONFIGURE DEVICE TYPE sbt PARALLELISM 2;
CONFIGURE DEFAULT DEVICE TYPE TO sbt;
CONFIGURE CHANNEL DEVICE TYPE sbt
RATE 1M;
In effect, the RATE option throttles RMAN so that a backup job does not consume
excessive I/O bandwidth on the computer.
结果就是RATE选项限制了RMAN，所以备份任务不会占用昂贵的IO带宽在电脑上。
