Diablo: ULLtraDIMM - CLI Managing Devices
Device Management Commands
This section describes the commands that are used to manage devices:
- online mode
- maintenance mode
- attach to group
- enabling TRIM
- disabling TRIM
- commit mode strategy
- device alias
- device configuration
Put device in online mode
The online parameter of the device command is used to put a device in online mode after it was put in maintenance mode for certain tasks, such as formatting a device or enabling or disabling TRIM.
[root@mcs ~]# td-cli device tda --online
Device tda is already onlinePut device in maintenance mode
The maintenance parameter of the device command is used to put a device in maintenance mode. Maintenance mode is required for several tasks on the device, such as formatting a device or enabling or disabling TRIM.
[root@mcs ~]# td-cli device tda --maintenance
Device tda successfully put into maintenance modeAttach device to group
Processor affinity is set by attaching a device to a group. Device groups are used to ensure that devices are using specific CPUs. Each device must be attached to a group. A device can be migrated from one group to another by attaching it to a new group.
The attach parameter of the device command is used to attach a device to a group.
[root@mcs ~]# td-cli device tdd --attach td-cpu-28
Device tdd successfully added to group td-cpu-28Enable TRIM
The TRIM command enables the host to communicate to the device that blocks of data have been de-allocated. As a result, the device is able to return those blocks to the pool of available unused blocks, which enables the device to maintain a higher level of background/overhead efficiency, minimizing subsequent Write Amplification and improving performance.
TRIM is disabled on each device by default. Operating systems that do not support TRIM ignore this setting.
To enable TRIM, use the trim on parameter of the device command.
N.B. - The device must be in maintenance mode to enable TRIM
[root@mcs ~]# td-cli device tda --maintenance
Device tda successfully put into maintenance mode
[root@mcs ~]# td-cli device tda --trim on
TRIM has been turned on for device tda