使用 scsi cmd 获取设备最大链接速度

Question

我正在寻找可用于获取设备最大 link 能力的 scsi 命令。

我可以使用 scsi MODE SENSE（第 19 页）读取 phy 描述符并获得 link 速度吗？但它与最大 link 速度和协商 link 速度有何不同？

Answer 1

根据 SPL-4，您使用 SMP DISCOVER 功能或 SCSI MODE SENSE 页面 19h Protocol Specific Port、子页面 01h Phy Control And Discover。

对于link速度，你应该使用NEGOTIATED LOGICAL LINK RATE。最大link速度为HARDWARE MAXIMUM PHYSICAL LINK RATE（物理限制）和PROGRAMMED MAXIMUM PHYSICAL LINK RATE（由PHY CONTROL功能配置）

这是使用SMP DISCOVER方式的例子：

[fge@el7 ~]$ sudo smp_discover /dev/bsg/expander-0\:0
  phy   0:T:attached:[500015535990a300:00  t(SATA)]  3 Gbps
  phy   1:T:attached:[500015535990a301:00  t(SATA)]  3 Gbps
  phy   2:T:attached:[500015535990a302:00  t(SATA)]  1.5 Gbps
  phy   3:T:attached:[500015535990a303:00  t(SATA)]  3 Gbps
  phy   4:T:attached:[500015535990a304:00  t(SATA)]  3 Gbps
  phy   5:T:attached:[500015535990a305:00  t(SATA)]  3 Gbps
  phy   6:T:attached:[500015535990a306:00  t(SATA)]  3 Gbps
  phy   7:T:attached:[500015535990a307:00  t(SATA)]  3 Gbps
  phy   8:T:attached:[500015535990a308:00  t(SATA)]  3 Gbps
  phy   9:T:attached:[500015535990a309:00  t(SATA)]  3 Gbps
  phy  10:T:attached:[500015535990a30a:00  t(SATA)]  3 Gbps
  phy  11:T:attached:[500015535990a30b:00  t(SATA)]  3 Gbps
  phy  12:T:attached:[500015535990a30c:00  t(SATA)]  3 Gbps
  phy  13:T:attached:[500015535990a30d:00  t(SATA)]  3 Gbps
  phy  14:T:attached:[50014ee5aaab876f:01  t(SSP)]  3 Gbps
  phy  15:T:attached:[500015535990a30f:00  t(SATA)]  3 Gbps
  phy  16:S:attached:[5d4ae520995f8200:03  i(SSP+STP+SMP)]  3 Gbps
  phy  20:T:attached:[500015535956633f:16 exp i(SMP) t(SMP)]  3 Gbps
  phy  21:T:attached:[500015535956633f:17 exp i(SMP) t(SMP)]  3 Gbps
  phy  22:T:attached:[500015535956633f:18 exp i(SMP) t(SMP)]  3 Gbps
  phy  23:T:attached:[500015535956633f:19 exp i(SMP) t(SMP)]  3 Gbps
  phy  24:D:attached:[500015535990a33e:24  V i(SSP) t(SSP)]  3 Gbps

使用 scsi cmd 获取设备最大链接速度

Get Device max links speed with scsi cmd

scsi