Managing extent space efficient DASDs

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest KVM guest

Thin provisioning is a method of optimizing space in a SAN, and can therefore affect the amount of storage capacity that you need. Storage systems with the thin provisioning feature can provide Extent Space Efficient (ESE) ECKD DASD.

About this task

The Linux® kernel recognizes ESE DASDs. You can set them online and use them as usual, without taking any special action.

Procedure

To find out if a DASD is an ESE DASD, check the ese attribute of the device in sysfs. An attribute value of 1 identifies the device as an ESE DASD.

For example, for a DASD with device-bus ID 0.0.95d0:

# cat /sys/bus/ccw/devices/0.0.95d0/ese
1

Alternatively, you can use the lsdasd command, see lsdasd - List DASD devices.