Sensor Readings: false positives for failed components #17

NX-06 commented 2023年12月13日 12:42:23 +01:00

The command 'ipmitool sdr' will output false/misleading information for sensor status of failed components.

Ipmitool version 1.8.19

This is repeatable by disconnecting fans or PSU from the motherboard during operation to simulate failures.
Turning off power to a PSU does not recreate the issue.
Removing the PSU/Fan entirely during operation is necessary.

Used Hardware:
Supermicro AS-1115CS-TNR
H13SSW FW(BIOS/BMC): 1.6/01.01.08

Output for sensors that have been removed during operation will read:
FAN1 | 0 RPM | ok
PS1 Status | 0x00 | ok

Expected behaviour for removed/failed is not a status of 'ok' but 'Critical' or similar warning.

This is not a bug on the manufacturer's side. The IPMI Web-GUI and other propietary management tools of Supermicro show the status as expected as 'Critical'.
Ipmiutil (version 3.1.8-4) shows the status correct as 'absent' as well.
But Freeipmi (version 1.6.10-1) shares the same bug as ipmitool.

The command 'ipmitool sdr' will output false/misleading information for sensor status of failed components. Ipmitool version 1.8.19 This is repeatable by disconnecting fans or PSU from the motherboard during operation to simulate failures. Turning off power to a PSU does not recreate the issue. Removing the PSU/Fan entirely during operation is necessary. Used Hardware: Supermicro AS-1115CS-TNR H13SSW FW(BIOS/BMC): 1.6/01.01.08 Output for sensors that have been removed during operation will read: FAN1 | 0 RPM | ok PS1 Status | 0x00 | ok Expected behaviour for removed/failed is not a status of 'ok' but 'Critical' or similar warning. This is not a bug on the manufacturer's side. The IPMI Web-GUI and other propietary management tools of Supermicro show the status as expected as 'Critical'. Ipmiutil (version 3.1.8-4) shows the status correct as 'absent' as well. But Freeipmi (version 1.6.10-1) shares the same bug as ipmitool.

AlexanderAmelkin commented 2025年11月11日 15:46:08 +01:00

Web-GUI can't be taken in account as it most certainly does NOT use IPMI protocol to get the information.
Apparenly it IS the problem on the manufacturer's side as the BMC firmware must indicate absence of the sensor by setting the 'reading unavailable' bit (bit 5 of byte 1 of the response to Get Sensor Reading command). Apparenly, it doesn't do that, otherwise you'd get the ns instead of ok.

It is unclear why and how ipmiutil reports an absent status.

For further investigation, please attach (as a file) the output of ipmitool -vvvvvv sdr

Web-GUI can't be taken in account as it most certainly does NOT use IPMI protocol to get the information. Apparenly it IS the problem on the manufacturer's side as the BMC firmware must indicate absence of the sensor by setting the 'reading unavailable' bit (bit 5 of byte 1 of the response to Get Sensor Reading command). Apparenly, it doesn't do that, otherwise you'd get the `ns` instead of `ok`. It is unclear why and how `ipmiutil` reports an absent status. For further investigation, please attach (as a file) the output of `ipmitool -vvvvvv sdr`