showdisk Command

Displays NAN flash drive information.

Syntax

showdisk

Description

This hardware command displays comprehensive status and life information about the NAN flash drive within the management controller. This drive is the repository of the firmware, operating system, and filesystem of the management controller.

The NAN flash technology is limited to a finite number of data erases to memory cells, in that each erase to the cell “ages” the cell. Once the age limit is exceeded, the memory cell is “dead” as it can no longer reliably store data. To extend the life of a NAN flash drive, when data is written, it is written to new locations throughout the group, and the file allocation table is accordingly updated.

For example, instead of erasing and writing data to the same memory cell over the course of five writes, the data is written to five different memory cells, one per each write. The file allocation table is updated on each write to point to the memory cell with the most current data. Though the previous memory cells still contain data, they are considered empty and are not erased until they are needed to receive different data writes in the future.

The output of the showdisk command includes:

• FRUID type information – Model, serial number, and firmware version.

• SMART capabilities – Both supported and enabled.

• Average age – The average number of erases to any given memory cell within a group.

• Number of block erases – The total number of erases to all memory cells in a group.

• Number of blocks – Similar to clusters in hard drives, the blocks are the smallest group of memory that can be erased.

• Estimated life used – A calculated percentage of memory cells that are dead or soon to be dead, based upon current erasing behaviors and a finite number of erases per memory cell.

• Estimated life remaining – 100% minus estimated life used.

The showdisk command is available from the /SYS/Switch_Diag and /SYS/Fabric_Mgmt Linux shell targets of the Oracle ILOM CLI interface.

Example

This example shows how to information about and status of the NAN flash drive with the showdisk command.

FabMan@gateway_name->showdisk 
 Device Model    :  512MB NANDrive
 Serial Number   :  0000000000A12o3ANCtx
 Firmware Version:  ND B642J
 
 SMART supported :  yes 
 SMART enabled   :  yes 
 
 Average age (4 groups):
     group 0:    221
     group 1:    190
     group 2:   3098
     group 3:      9
 
 Block erase count (4 groups):
     group 0:    216900
     group 1:    190567
     group 2:   3104711
     group 3:      9097
     Total  :   3521275
 
 Total physical blocks: 4096 
 
 Estimated Life Usage    :  3.098 %
 
 Estimated Remaining Life: 96.902 %
 
FabMan@gateway_name->

Related Information

• Switch Administration, displaying flash drive information

• showfree Command

• Linux Shells for Hardware Commands