chsystem
Use the chsystem command to modify the attributes of an existing system. Enter this command any time after a system is created. All the parameters that are associated with this command are optional. However, you must specify one or more parameters with this command.
Syntax
Parameters
- (Optional) Specifies a new name for the system.Important: The Internet Small Computer System Interface (iSCSI) Qualified Name (IQN) for each node is generated by using the system and node names. If you are using the iSCSI protocol, changing either name also changes the IQN of all of the nodes in the system and might require reconfiguration of all iSCSI-attached hosts.
- (Optional) Specifies the amount of memory, in megabytes (MB), to use on each node for
Metro Mirror and Global Mirror communications, from 48 to 512 MB. The default is 48 MB.
Important: Adjust this setting only when directed by your support team.
All nodes in the system must be online and have a minimum of 8 gigabytes (GB) - or 8192 megabytes (MB) - of memory to change this setting.
Remember:- Before changing this setting you must stop all partnerships with this system.
- This parameter operates on the local system only and changing it is disruptive to mirroring operations.
- (Optional) Specifies an alternative name that does not change the basic ID for the
system, but does influence the
VDisk_UID
of newly created volumes. ExistingVDisk_UIDs
are not changed. - (Optional) Specifies the interval at which inventory emails are sent to the designated
email recipients. The interval range is
0
to15
. The interval is measured in days. Setting the value to 0 turns off the inventory email notification function. - (Optional) Specifies the length of time, in seconds, for which an inadequate
intersystem link is tolerated for a Global Mirror operation. The parameter accepts
values from
20
to86400
seconds in steps of 10 seconds. The default is 300 seconds. You can disable the link tolerance by entering a value of0
for this parameter. - (Optional) Specifies the maximum time delay, in milliseconds, at which the Global Mirror link tolerance timer starts counting down. This threshold value determines the additional impact that Global Mirror operations can add to the response times of the Global Mirror source volumes. You can use this parameter to increase the threshold from the default value of 5 milliseconds.
- (Optional) Specifies the system's new IPv4 address that is used by the system. The
format of this IP address must be a dotted decimal notation with the port; for example,
255.255.255.255:8080
. If you specify this parameter, it overwrites any existing -icatip_6 address. - (Optional) Specifies the system's new IPv6 address. If you specify this parameter, it
overwrites any existing -icatip address. The format of the IPv6
address must be:
- (Optional) Specifies the IPv4/IPv6 address or fully qualified domain name (FQDN) for the
Network Time Protocol (NTP) server. The maximum number
of characters is 256. Configuring an NTP server address causes the system to use
that NTP server as its time source. Specify the -ntpip parameter with
a zero address to use another time source:
chsystem -ntpip 0.0.0.0
- Note: Before you specify -ntpip_6, an IPv6 prefix and gateway must be set for the system.(Optional) Specifies the IPv6 address for the NTP server. Configuring an NTP server address causes the system to immediately start using that NTP server as its time source. To choose another time source, specify the -ntpip_6 parameter with a zero address, as follows:
chsystem -ntpip_6 0::0
- (Optional) Specifies the IPv4 address for the iSCSI storage name service (SNS).
Specify the -isnsip parameter with a zero address to select another
IPv4 iSCSI SNS server:
chsystem -isnsip 0.0.0.0
- (Optional) Specifies the IPv6 address for the iSCSI SNS. Specify the
-isnsip_6 parameter with a zero address to select another
configured IPv6 iSCSI SNS server:
chsystem -isnsip_6 0::0
- (Optional) Specifies the new background copy bandwidth in megabytes per second (MBps),
from
1
to1000
. The default is25
MBps.This parameter operates system-wide and defines the maximum background copy bandwidth that any relationship can adopt. The existing background copy bandwidth settings that are defined on a partnership continue to operate, with the lower of the partnership and volume rates attempted.Note: Do not set this value higher than the default without establishing that the higher bandwidth can be sustained. - Specifies the preferred online documentation URL to override the one used by the GUI.
Because this information is interpreted by the Internet browser, the specified
information might contain a hostname or an IP address. Remember: View the currently configured URL in the GUI preferences window. This window can also help reset this value to the default setting.
- (Optional) Sets the authentication method for the iSCSI communications of the system:
- (Optional) Turns authentication on or off for remote copy partnership requests that
are native IP partnerships.
Additionally:
- (Optional) Sets the CHAP secret to be used to authenticate the system that uses iSCSI. This parameter is required if the iscsiauthmethod chap parameter is specified. The specified CHAP secret cannot begin or end with a space.
- (Optional) Clears any previously set CHAP secret for iSCSI authentication. The nochapsecret parameter cannot be specified when chapsecret is specified.
- (Optional) Specifies the user name for the entire SVC system that is used for two-way authentication for iSCSI host attach login. If this parameter is specified, this value is taken as "username" for two-way authentication in iSCSI host attach login. If user name is not specified, user name for two-way chap authentication is NULL.
- (Optional) Specifies which layer a system is in. The system can create partnerships
with systems in the same layer. Note: If you specify -layer you must specify either replication or storage. This option can be used if no other systems are visible on the fabric, and no system partnerships are defined.
- (Optional) Indicates whether cache prefetching is enabled or disabled across the system. Adjust this only when following direction from your product support information.
- (Optional) Indicates the Fibre Channel (FC) input/output (I/O) port mask for local
system node-to-node communications only. Fibre Channel port mask does not affect host or
storage system traffic. The port mask is 64 binary bits and is made up of a combination
of 0's and 1's, where
0
indicates that the corresponding FC I/O port cannot be used and1
indicates that it can be used. The mask is applied to all nodes in the local system. At least two ports must be selected for local system node-to-node communications. The mask must result in at least 2 FC connections between each node in the local system, using only the selected ports and FC zones visible to those ports. Valid mask values might range from0011
(only ports 1 and 2 enabled) to1111111111111111111111111111111111111111111111111111111111111111
(all ports enabled). For example, a mask of111111101101
enables ports 1, 3, 4, 6, 7, 8, 9, 10, 11, and 12.Remember: A partial mask (fewer than 64 characters) is zero-extended, meaning that any ports that are not specified are not enabled.Specify the lsportfc command to display FC I/O port IDs. - (Optional) Indicates the FC I/O port mask for partnered system-to-system
communications only. Fibre Channel port mask does not affect host or storage system
traffic. The port mask is 64 binary bits and is made up of a combination of 0's and 1's,
where
0
indicates that the corresponding FC I/O port cannot be used and1
indicates that it can be used. The mask is applied to all nodes in the local system. Valid mask values might range from0000
(no ports enabled) to1111111111111111111111111111111111111111111111111111111111111111
(all ports enabled). For example, a mask of111111101101
enables ports 1, 3, 4, 6, 7, 8, 9, 10, 11, and 12.Remember: A partial mask (fewer than 64 characters) is zero-extended, meaning that any ports not specified are not enabled.Specify the lsportfc command to display FC I/O port IDs. - (Optional) Indicates the intended system topology, which is either standard or hyperswap.
- (Optional) Sets volume protection time (in minutes). The range is 15 - 1440.
- (Optional) Enables or disables volume protection. The values are
yes
andno
. - (Optional) Enables or disables offloaded data transfers (ODX). The values are
on
andoff
. - (Optional) Enables Easy Tier® and pool
balancing acceleration. The values are
on
andoff
. - (Optional) Sets a maximum replication delay in seconds. The value must be a number
from
0
to360
. - (Optional) Sets the timeout for an I/O operation (in seconds) for remote systems. The
value must be a number from
30
to315
(default). - (Optional) Specifies that the call home function is to send enhanced reports to the
support center. Valid values are
yes
orno
.The enhanced reports include operational and event-related data and specific configuration information that is included in the inventory report. This function alerts the support center about hardware failures and potentially serious configuration or environmental issues. The support center can use the configuration information to automatically generate best practices or recommendations that are based on your actual configuration.
- (Optional) Specifies that sensitive data is deleted from the enhanced call home data.
The values are
yes
orno
. - (Optional) Specifies whether the administrator wants the volumes to advertise support
for unmap to hosts. The values are
on
(default) oroff
. - (Optional) Specifies whether the administrator wants to enable SCSI Unmap support for
backend storage. Enabling this parameter allows the system to issue SCSI Unmap or Write
Same commands to compatible backend storage controllers and drives to reclaim capacity
when capacity is freed within the system. The values are
on
(default) oroff
. - (Optional) Specifies the mode that quorum uses for tie-breaking. The valid values are standard (default), preferred, or winner.
- (Required) Specifies the site ID or name that quorum uses for tie-breaking when -quorummode is set to preferred or winner.
- (Optional) Specifies the mode that quorum uses for tie-breaking. The valid values are short (default) or long.
Description
This command modifies specific features of a system. Multiple features can be changed by issuing a single command.
Using the -ntpip or -ntpip_6 parameter allows the system to use an NTP server as an outside time source. The system adjusts the system clock of the configuration node according to time values from the NTP server. The clocks of the other nodes are updated from the configuration node clock. In the NTP mode, the setsystemtime command is disabled.
All command parameters are optional, but you must specify at least one parameter.
Use the chsystemip command to modify the system IP address and service IP address.
An invocation example
chsystem -ntpip 9.20.165.16
The resulting output:
No feedback
An invocation example to set up an external NTP server
chsystem -ntpip 123.234.123.234
The resulting output:
No feedback
An invocation example to change the preferred
infocenterurl
value
chsystem -infocenterurl http://miscserver.company.com/ibm/infocenter
The resulting output:
No feedback
An invocation example to change the local port mask value
To indicate that FC I/O ports with IDs 3 and 4 of an eight port system are capable of local node communication:
chsystem -localfcportmask 00001100
The resulting output:
No feedback
An invocation example to change the partner port mask value
To indicate that FC ports with IDs 7 and 8 of an eight port system are capable of remote node communication:
chsystem -partnerfcportmask 11000000
The resulting output:
No feedback
An invocation example to set authentication for remote copy
chsystem -chapsecret ABCB1234 -iscsiauthmethod none -rcauthmethod chap
The resulting output:
No feedback
An invocation example to turn off volume protection
chsystem -vdiskprotectionenabled no
The resulting output:
No feedback
An invocation example to turn on volume protection and set the protection time to 60 minutes
chsystem -vdiskprotectionenabled yes -vdiskprotectiontime 60
The resulting output:
No feedback
An invocation example to turn on Easy Tier acceleration
chsystem -easytieracceleration on
The resulting output:
No feedback
An invocation example to turn on ODX
chsystem -odx on
The resulting output:
No feedback
An invocation example to set the maximum replication delay
chsystem -maxreplicationdelay 100
The resulting output:
No feedback
An invocation example to set the partnership exclusion threshold
chsystem -partnershipexclusionthreshold 120
The resulting output:
No feedback
An invocation example to turn off enhanced call home
chsystem -enhancedcallhome off
The resulting output:
No feedback
An invocation example to turn on censor call home
chsystem -censorcallhome on
The resulting output:
No feedback
An invocation example to turn on hostunmap and backendunmap
chsystem -hostunmap on -backendunmap on
The resulting output:
No feedback
An invocation example
chsystem -ntpip myntpserver.mycompany.com
The resulting output:
No feedback