chchp - Change channel path status

SUSE Linux Enterprise Server 15 SP5 LPAR mode z/VM guest KVM guest

Purpose

Use the chchp command to set channel paths online or offline.

The actions are equivalent to performing a Configure Channel Path Off or Configure Channel Path On operation on the Hardware Management Console.

The channel path status that results from a configure operation is persistent across IPLs.

Note: Changing the configuration state of an I/O channel path might affect the availability of I/O devices. It can also trigger associated functions (such as channel-path verification or device scanning), which in turn can result in a temporary increase in processor, memory, and I/O load.

chchp syntax

Where:

-c <value> or --configure <value>: sets the device to configured (1) or standby (0).
Note: Setting the configured state to standby can stop running I/O operations.
-v <value> or --vary <value>: changes the logical channel-path state to online (1) or offline (0).
Note: Setting the logical state to offline can stop running I/O operations.
-a <key> = <value> or --attribute <key> = <value>: changes the channel-path sysfs attribute <key> to <value>. The <key> can be the name of any available channel-path sysfs attribute (that is, configure or status), while <value> can take any valid value that can be written to the attribute (for example, 0 or offline). Using -a is a generic way of writing to the corresponding sysfs attribute. It is intended for cases where sysfs attributes or attribute values are available in the kernel but not in chchp.
0.<id> and 0.<id> - 0.<id>: where <id> is a hexadecimal, two-digit, lowercase identifier for the channel path. An operation can be performed on more than one channel path by specifying multiple identifiers as a comma-separated list, or a range, or a combination of both.
--version: displays the version number of chchp and exits.
-h or --help: displays a short help text, then exits. To view the man page, enter man chchp.

Examples

To set channel path 0.19 into standby state issue:
```
# chchp -a configure=0 0.19
```
To set the channel path with the channel path ID 0.40 to the standby state, write 0 to the configure file with the chchp command:
```
# chchp --configure 0 0.40
Configure standby 0.40... done.
```
To set a channel-path to the configured state, write 1 to the configure file with the chchp command:
```
# chchp --configure 1 0.40
Configure online 0.40... done.
```
To set channel-paths 0.65 to 0.6f to the configured state issue:
```
# chchp -c 1 0.65-0.6f
```
To set channel-paths 0.12, 0.7f and 0.17 to 0.20 to the logical offline state issue:
```
# chchp -v 0 0.12,0.7f,0.17-0.20
```