chccwdev - modify generic attributes of channel attached devices.
- [ (-a
<name>=<value> | -e | -d |
-s | -f) [...]]
<range> [, <range> [...]]
The chccwdev command is used to set generic attributes for devices that are
controlled by the common I/O subsystem. Attributes are set in the order they
are specified on the commandline except the online attribute which is special.
If the same attribute is given more than one time the value that was set last
will be used. This is also true (while not that obvious) when mixing the
and the -e
All attributes will be set in the following order:
- All attributes except online. If the device is offline
there will be no error if the attribute doesn't exist.
- Set the online attribute to the desired value ((forced)
online or (safe) offline).
- Set all the attributes that havn't been set, yet. At this
point invalid attribute names will always cause an error.
If any error occurs the execution is terminated. So if using ranges only devices
before the current one have been modified. There is no automatic rollback. All
attributes that already have been changed will stay that way.
- Print help text.
- Print the version of the s390-tools package and the
- Try to set the attribute named name to the given
value. After writing the attribute it will be read to check whether the
setting was accepted.
- Try to set the specified devices online.
- Same as online but for devices that support this (DASD
devices), it can be used to bring it online regardless of any reserved
- Try to set the specified devices offline. The --online,
--forceonline, --offline, and --safeoffline options are mutually
- DASD only: For each specified device, wait until all
outstanding I/O requests have completed, and then try to set the device
offline. The --online, --forceonline, --offline, and --safeoffline options
are mutually exclusive.
- <range> = <bus ID>[-<bus
chccwdev --online 0.0.0192,0.0.0195-0.0.0198
- <bus ID> =
- Note that bus IDs specified in short form (i.e. without
leading "0.<n>.") will be interpreted as "0.0.<bus
Example: "0192" becomes "0.0.0192".
After completing all outstanding I/O requests
for the devices with bus ID 0.0.0192, 0.0.0195, 0.0.0196, 0.0.0197 and
0.0.0198, tries to set the device offline.
chccwdev --attribute readonly=1 --attribute online=1 0.0.0192
This will try to set the device with bus ID
0.0.192 online with readonly attribute set to one (read-only mode).
chccwdev --attribute cmb_enable=1 0.0.0195-0.0.0198
Set the cmb_enable attribute of the devices
0.0.0195, 0.0.0196, 0.0.0197 and 0.0.0198 to one. This would for example
activate the usage of the channel measurement block facility.
chccwdev --safeoffline 0.0.0192,0.0.0195-0.0.0198
Will try to set the devices with bus ID
0.0.0192, 0.0.0195, 0.0.0196, 0.0.0197 and 0.0.0198 offline and finish all
outstanding I/O requests before.
This man-page was written by Stefan Bader <email@example.com>.