文章目录
为什么当服务器配置了RAID卡时，需要将“Advanced >MISC config”界面中参数“Support Smmu”设置为“Disabled”?
"SMMU"代表系统内存管理单元(System Memory Management Unit)，它是一种硬件设备，负责处理来自设备的I/O访问请求，并将其转换为适当的物理内存地址。这样，设备可以直接访问主机的内存，而无需通过CPU。
但是，有些设备，包括某些RAID卡，可能与SMMU不兼容。如果在这种情况下启用SMMU，可能会导致各种问题，包括性能下降、数据错误甚至系统崩溃。
对于Avago SAS3408iMR/Avago SAS3416iMR RAID卡，制造商可能已经知道了这种不兼容性，并推荐在使用这些设备时禁用SMMU。
请注意，这只是一种可能的解释。在修改任何系统设置之前，你应该查阅相关设备的文档或联系制造商以获取确切的建议。
为什么当服务器配置了RAID卡时，需要将“Advanced >MISC config”界面中参数“Support SPCR”设置为“Disabled”?
“Support SPCR” 是一个用于支持串行控制台重定向的 BIOS 设置，这意味着它允许服务器通过串行端口进行管理和配置。然而，对于某些 RAID 卡（如 Avago SAS3408iMR/Avago SAS3416iMR），如果启用了“Support SPCR”，可能会导致与 RAID 卡的通信问题或冲突。
具体地说，开启“Support SPCR”可能会占用一部分 I/O 地址空间，影响到 RAID 卡的正常工作。例如，RAID 卡可能无法被操作系统正确识别，或者无法正常初始化。所以，在配置包含这类 RAID 卡的服务器时，需要将“Support SPCR”设置为“Disabled”，即禁用此功能，来确保 RAID 卡能够正常工作。
参考文章
Ubuntu 20.04 操作系统 安装指导书 (鲲鹏920处理器)
raid卡配置教程（基于Ubuntu 20.04 操作系统安装指导书 (鲲鹏 920 处理器)安装）
ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ
ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ
ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ
ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ
ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ ᅟᅠ