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 ECKD type DASD.
About this task
The extended error reporting feature is turned off 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, /dev/dasd_eer. 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.