Using extended error reporting for ECKD type DASD
Control the extended error reporting feature for individual ECKD type DASD through the eer_enabled sysfs attribute. Use the character device of the extended error reporting module to obtain error records.
Before you begin
To use the extended error reporting feature, you need:
- A kernel that includes the extended error reporting feature, either compiled into the kernel or as a separate module.
- A misc character device.
- ECKD type DASD
About this task
The extended error reporting feature is disabled by default.
Procedure
To enable extended error reporting, issue a command of
this form:
# echo 1 > /sys/bus/ccw/devices/<device_bus_id>/eer_enabledwhere /sys/bus/ccw/devices/<device_bus_id> represents
the device in sysfs.
When it is enabled on a device, a specific set of errors generates records and might have further side effects.
To disable extended error reporting, issue a command
of this form:
# echo 0 > /sys/bus/ccw/devices/<device_bus_id>/eer_enabledWhat to do next
You can obtain error records for all DASD for which extended error reporting is enabled from the character device of the extended error reporting module, . The device supports these file operations:
- open
- Multiple processes can open the node concurrently. Each process that opens the node has access to the records that are created from the time the node is opened. A process cannot access records that were created before the process opened the node.
- close
- You can close the node as usual.
- read
- Blocking read and non-blocking read are supported. When a record is partially read and then purged, the next read returns an I/O error -EIO.
- poll
- The poll operation is typically used with non-blocking read.