chsystem

Parameters

-namesystem_name

(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.

-rcbuffersizenew_size_in_MB

(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.

-aliasid_alias

(Optional) Specifies an alternative name that does not change the basic ID for the system, but does influence the VDisk_UID of every vdiskhostmap, both existing and new. These objects are created for a system whose ID matches the alias. Therefore, changing the system alias causes loss of host system access until each host scans for volumes that are presented by the system.

-invemailintervalinterval

(Optional) Specifies the interval at which inventory emails are sent to the designated email recipients. The interval range is 0 to 15. The interval is measured in days. Setting the value to 0 turns off the inventory email notification function.

-gmlinktolerancelink_tolerance

(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 to 86400 seconds in steps of 10 seconds. The default is 300 seconds. You can disable the link tolerance by entering a value of 0 for this parameter.

-gmmaxhostdelaymax_host_delay

(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.

-icatipicat_console_ip_address

(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.

-icatip_6icat_console_ipv6_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:

• Eight colon-separated groups of four hexadecimal digits; for example:

  [1234:1234:abcd:0123:0000:0000:7689:6576]:23

• Eight colon-separated groups of hexadecimal digits with leading zeros omitted; for example:

  [1234:1234:abcd:123:0:0:7689:6576]:23

• Suppression of one or more consecutive all 0 groups; for example:

  [1234:1234:abcd:123::7689:6576]:23

-ntpipipv4_ntp_ip_address

(Optional) Specifies the IPv4 address for the Network Time Protocol (NTP) server. 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

-ntpip_6ipv6_ntp_ip_address

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

-isnsipsns_server_address

(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

-isnsip_6ipv6_sns_server_address

(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

-relationshipbandwidthlimitbandwidth_in_mBps

(Optional) Specifies the new background copy bandwidth in megabytes per second (MBps), from 1 to 1000. The default is 25 MBps.

Important: For partnerships over IP links with compression, this parameter specifies the aggregate bandwidth after compression was applied to the data. Do not set this parameter higher than the physical link bandwidth multiplied by the (carefully rounded down) compression factor.

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.

-infocenterurlurl

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.

-iscsiauthmethodnone | chap -chapsecret chap_secret

(Optional) Sets the authentication method for the iSCSI communications of the system:

• chap indicates Internet Small Computer System Interface (iSCSI) authentication is turned on.
  Remember: This turns on iSCSI partnership authentication when a Challenge Handshake Authentication Protocol (CHAP) secret key is set for the system.
• none indicates that iSCSI partnership authentication is turned off.

-rcauthmethodnone | chap -chapsecret chap_secret

(Optional) Turns authentication on or off for remote copy partnership requests that are native IP partnerships. Remote copy includes Metro Mirror, Global Mirror, and HyperSwap. Additionally:

• chap indicates that remote copy authentication is turned on.
  Remember: This action turns on authentication of remote copy partnership requests when a Challenge Handshake Authentication Protocol (CHAP) secret key is set for the system.
• none indicates that remote copy partnership authentication is turned off.

-chapsecretchap_secret

(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.

-nochapsecret

(Optional) Clears any previously set CHAP secret for iSCSI authentication. The nochapsecret parameter cannot be specified when chapsecret is specified.

-iscsiusername

(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.

-layerreplication | storage

(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.

-cacheprefetchon | off

(Optional) Indicates whether cache prefetching is enabled or disabled across the system. Adjust this only when following direction from your product support information.

-localfcportmaskport_mask

(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 and 1 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 from 0011 (only ports 1 and 2 enabled) to 1111111111111111111111111111111111111111111111111111111111111111 (all ports enabled). For example, a mask of 111111101101 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.

-partnerfcportmaskport_mask

(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 and 1 indicates that it can be used. The mask is applied to all nodes in the local system. Valid mask values might range from 0000 (no ports enabled) to 1111111111111111111111111111111111111111111111111111111111111111 (all ports enabled). For example, a mask of 111111101101 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.

-hightempmodeon | off

(Optional) Sets (or removes) High Temperature Mode (HTM). The values are on and off.

-topologystandard | hyperswap

(Optional) Indicates the intended system topology, which is either standard or hyperswap.

-vdiskprotectiontimevalue_in_minutes

(Optional) Sets volume protection time (in minutes).

-vdiskprotectionenabledyes | no

(Optional) Enables or disables volume protection. The values are yes and no.

-odxon | off

(Optional) Enables or disables offloaded data transfers (ODX). The values are on and off.

-easytieraccelerationon | off

(Optional) Enables Easy Tier and pool balancing acceleration. The values are on and off.

-maxreplicationdelayvalue_in_seconds

(Optional) Sets a maximum replication delay in seconds. The value must be a number from 0 to 360.

-partnershipexclusionthresholdvalue_in_seconds

(Optional) Sets the timeout for an I/O operation (in seconds) for remote systems. The value must be a number from 30 to 315 (default).

-enhancedcallhomeon | off

(Optional) Specifies that the call home function is to send enhanced reports to the support center. Valid values are yes or no.

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.

-censorcallhomeon | off

(Optional) Specifies that sensitive data is deleted from the enhanced call home data. The values are yes or no.

-hostunmapon | off

(Optional) Specifies whether the administrator wants the volumes to advertise support for unmap to hosts. The values are on or off (default).

-backendunmapon | off

(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) or off.