红帽全球峰会26.8. systemd 的 I/O 带宽配置选项
要使用 systemd 管理块层 I/O 策略，可以使用以下配置选项：
IOWeight- 设置默认 I/O 权重。权重值用作计算服务与其他服务相比实际 I/O 带宽数量的基础。
IODeviceWeight设置特定块设备的 I/O 权重。
注意只有在块设备使用 CFQ I/O 调度程序时，才支持基于权重的选项。如果设备使用了多队列块 I/O 排队机制，则不支持选项。
例如，IODeviceWeight=/dev/disk/by-id/dm-name-rhel-root 200。
IOReadBandwidthMax,IOWriteBandwidthMax设置每个设备或挂载点的绝对带宽。
例如：
IOWriteBandwith=/var/log 5M。注意systemd自动处理文件系统-到-设备转换。IOReadIOPSMax、IOWriteIOPSMax- 每秒输入/输出操作中设置绝对带宽(IOPS)。
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