Managing Regions

Last updated 6 months ago

A region is a grouping of one or more NVDIMMs, or an interleaved set, that can be divided up into one or more Namespaces. Regions are of type PMEM or BLK. See PMEM or BLK modes for more information. The type can only be changed using the vendor specific NVDIMM utility that manages the NVDIMMs and/or a BIOS option if available.

Disabling Regions

1) List all active/enabled regions:

# ndctl list -R
{
"dev":"region0",
"size":134217728000,
"available_size":134217728000,
"type":"pmem",
"numa_node":0,
"iset_id":-7501067817058727390,
"state":"disabled",
"persistence_domain":"memory_controller"
}

A filtered list of active/enabled regions can be displayed using the -r <region-id> or --region <region-id> option, eg:

# ndctl list -R -r region0
- or -
# ndctl list -R -region region0

2) Disable the region

# ndctl disable-region region0
disabled 1 region

3) Verify the region is disabled by including the -i option:

# ndctl list -Ri
{
"dev":"region0",
"size":134217728000,
"available_size":134217728000,
"type":"pmem",
"numa_node":0,
"iset_id":-7501067817058727390,
"state":"disabled",
"persistence_domain":"memory_controller"
}

A filtered list of disabled/inactive regions can be displayed using the -r <region-id> or --region <region-id> option, eg:

# ndctl list -Ri -r region0
- or -
# ndctl list -Ri -region region0

Enabling Regions

1) List disabled/inactive regions

# ndctl list -Ri
{
"dev":"region0",
"size":134217728000,
"available_size":134217728000,
"type":"pmem",
"numa_node":0,
"iset_id":-7501067817058727390,
"state":"disabled",
"persistence_domain":"memory_controller"
}

A filtered list of active/enabled regions can be displayed using the -r <region-id> or --region <region-id> option, eg:

# ndctl list -R -r region0
- or -
# ndctl list -R -region region0

2) Enable the region

# ndctl enable-region region0
enabled 1 region

3) Verify the region is enabled using ndctl list -R. Note the 'state' field is not displayed for enabled regions.

# ndctl list -R
{
"dev":"region0",
"size":134217728000,
"available_size":134217728000,
"type":"pmem",
"numa_node":0,
"iset_id":-7501067817058727390,
"persistence_domain":"memory_controller"
}