IBM General Parallel File System for AIX: Administration and Programming Reference

Displaying GPFS disk states

You can display the current state of one or more disks in your file system by issuing the mmlsdisk command. The information includes parameters that were specified on the mmcrfs command, and the current availability and status of the disks. For example, to display the current status of the disk gpfslv09 in the file system fs1, enter:

mmlsdisk fs1 -d "gpfslv09"

Status will be displayed in the format:

disk         driver   sector failure holds    holds                             
name         type       size   group metadata data  status        availability  
------------ -------- ------ ------- -------- ----- ------------- ------------  
gpfslv09     disk        512      -1 yes      yes   ready         up 
 

Refer to mmlsdisk Command for syntax and usage information.

Availability

A disk's availability determines whether GPFS is able to read and write to the disk. There are four possible values for availability:

up

The disk is available to GPFS for normal read and write operations

down

No read and write operations can be performed on the disk

recovering

An intermediate state for disks coming up, during which GPFS verifies and corrects data. read operations can be performed while a disk is in this state but write operations cannot.

unrecovered

Not all disks were successfully brought up

Disk availability is automatically changed from up to down when GPFS detects repeated I/O errors. You can also change the availability of a disk by issuing the mmchdisk command.

Status

Disk status controls data placement and migration. Status changes as a result of a pending delete operation, or when the mmchdisk command is issued to allow file rebalancing or rereplicating prior to disk replacement or deletion.

Disk status has five possible values, but three are transitional:

ready

Normal status

suspended

Indicates that data is to be migrated off this disk

being emptied

Transitional status in effect while a disk deletion is pending

replacing

Transitional status in effect for old disk while replacement is pending

replacement

Transitional status in effect for new disk while replacement is pending

GPFS allocates space only on disks with a status of ready or replacement.

GPFS migrates data off of disks with a status of being emptied, replacing, or suspended, onto disks with a status of ready or replacement. During disk deletion or replacement, data is automatically migrated as part of the operation. The mmrestripefs command must be issued to initiate data migration from a suspended disk.

See Deleting disks from a file system, Replacing disks in a GPFS file system, and Restriping a GPFS file system.