Module parameters

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7.1 LPAR mode z/VM guest KVM guest

If the base module of the DASD device driver has been built as a separate module, you configure the device driver through module parameters. You specify these parameters when you are loading the base module.

Any components of the DASD device driver that have been compiled as separate modules must be loaded before they can be used.

Figure 1. DASD module parameter syntax

1  modprobe
2.1  dasd_mod ? dasd=
2.2.1+ ,
2.2.1 %device-spec
2.2.1 autodetect
2.2.1 probeonly
2.2.1 nopav
2.2.1 nofcx
2.2.1? eer_pages=<pages>
2.2.1! eer_pages=5
2.1 dasd_eckd_mod
2.1 dasd_fba_mod
2.1 dasd_diag_mod
device-spec

1 
2.1 <device_bus_id>
2.1 <from_device_bus_id>-<to_device_bus_id>
2.1 ipldev
1? (
2.1+ :
2.1 ro
2.1 diag
2.1 erplog
2.1 failfast
1)
Where:
dasd_mod
loads the device driver base module.

When you are loading the base module, you can specify the dasd= parameter. The variables and key words have the same meaning as the corresponding kernel parameters.

If the extended error reporting feature is compiled into this module, you can use the eer_pages parameter to determine the number of pages that are used for internal buffering of error records.

dasd_eckd_mod
loads the ECKD™ module.
dasd_fba_mod
loads the FBA module.
dasd_diag_mod
loads the DIAG module.

The DASD base component is required by the other modules. modprobe takes care of this dependency for you and ensures that the base module is loaded automatically, if necessary.

Hint: modprobe might return before udev has created all device nodes for the specified DASDs. If you need to assure that all nodes are present, for example in scripts, follow the modprobe command with: 
# udevadm settle

For command details see the modprobe man page.

Examples

The following example specifies a range of DASD devices and two individual DASD devices: 
# modprobe dasd_mod dasd=0.0.7000-0.0.7002,0.0.7005(ro),0.0.7006
For the same mainframe setup, the resulting allocation of device nodes and minor numbers would be as shown in the following table:
Table 1. Example mapping of device names and minor numbers to devices
Minor Name To access
0 dasda device 0.0.7000 as a whole
1 dasda1 the first partition on 0.0.7000
2 dasda2 the second partition on 0.0.7000
3 dasda3 the third partition on 0.0.7000
4 dasdb device 0.0.7001 as a whole
5 dasdb1 the first partition on 0.0.7001
6 dasdb2 the second partition on 0.0.7001
7 dasdb3 the third partition on 0.0.7001
8 dasdc device 0.0.7002 as a whole
9 dasdc1 the first partition on 0.0.7002
10 dasdc2 the second partition on 0.0.7002
11 dasdc3 the third partition on 0.0.7002
12 dasdd device 0.0.7005 as a whole
13 dasdd1 the first partition on 0.0.7005 (read-only)
14 dasdd2 the second partition on 0.0.7005 (read-only)
15 dasdd3 the third partition on 0.0.7005 (read-only)
16 dasde device 0.0.7006 as a whole
17 dasde1 the first partition on 0.0.7006
18 dasde2 the second partition on 0.0.7006
19 dasde3 the third partition on 0.0.7006
The following example specifies that High Performance FICON® are to be suppressed for all DASDs: 
# modprobe dasd_mod dasd=nofcx,4711-4713