Enable, disable, extend and view TRIM settings on an existing declustered array and file system

To enable or disable TRIM on a IBM Storage Scale RAID system

TRIM can be dynamically enabled or disabled on an existing declustered array and file system. TRIM must be enabled on a declustered array before you enable it at the file system level. When you disable TRIM, you must first disable it from the file system NSDs, and then from the declustered array.

Issue the mmvdisk recoverygroup change command with the --declustered-array --trim-da {yes|no} to specify the required TRIM settings on the declustered array and recovery group.

Issue the mmvdisk filesystem change command with the --trim {auto|no} option to specify the required TRIM settings on the file system.

To extend a TRIM-enabled IBM Storage Scale RAID system

A pdisk automatically inherits the TRIM setting of the DA to which it is added. The TRIM setting can be inherited when you scale-up or scale-out the recovery groups. You can either add an IBM Storage Scale Erasure Code Edition (ECE) node by using the mmvdisk recoverygroup add command to scale-out the ECE recovery group, or you can scale-up the ECE or IBM Storage Scale System recovery group by using the mmvdisk recoverygroup resize command.

For scale-out on ECE recovery group, the vdisk set will be extended automatically. The new vdisk NSDs in the vdisk set will inherit the TRIM setting in the file system.

For scale-up on ECE or IBM Storage Scale System recovery group, issue the mmvdisk filesystem add command with the option --trim {auto|no} to select TRIM settings when you are adding a vdisk set to a file system.

Note: The default TRIM setting while adding a new vdisk set to a file system is "no" irrespective of the TRIM settings of the existing vdisk sets.

To View TRIM Settings

TRIM settings are enabled at the File system and DA level. View the TRIM settings with the following commands:

# mmvdisk recoverygroup list --recovery-group rg1 --da

declustered   needs                vdisks       pdisks           capacity
   array     service  type  trim  user log  total spare rt  total raw free raw  background task
-----------  -------  ----  ----  ---- ---  ----- ----- --  --------- --------  ---------------
DA1          no       NVMe  yes      0  13     12     2  2   3839 GiB 1190 GiB  scrub 14d (63%)

mmvdisk: Total capacity is the raw space before any vdisk set definitions.
mmvdisk: Free capacity is what remains for additional vdisk set definitions.

# mmvdisk filesystem list --file-system mixfs

                                vdisk  with     list of       holds    holds  storage
vdisk set       recovery group  count  trim  failure groups  metadata  data    pool
--------------  --------------  -----  ----  --------------  --------  -----  -------
NVME            rg1                 4     4             1,2  no        yes    data
ESSDATA         rg1                 1     0               1  yes       yes    system