Use the chsystem command to modify the
attributes of an existing clustered system (system). Enter this command
any time after a system has been created. All the parameters that
are associated with this command are optional. However, you must specify
one or more parameters with this command.
Syntax
chsystem [ -name system_name ] [ -rcbuffersize new_size_in_MB ] [ -alias id_alias ] [ -icatip icat_console_ip_address ] [ -invemailinterval interval ] [ -gmlinktolerance link_tolerance ] [ -gmmaxhostdelay max_host_delay ] [ -icatip ipv4_icat_ip_address ] [ -icatip_6 ipv6_icat_ip_address ] [ -ntpip ipv4_ntp_ip_address ] [ -ntpip_6 ipv6_ntp_ip_address ] [ -isnsip sns_server_address ] [ -isnsip_6 ipv6_sns_server_address ] [ -relationshipbandwidthlimit bandwidth_in_mBps ] [ -infocenterurl url ] [ -iscsiauthmethod { none | chap -chapsecret chap_secret } ] [ -rcauthmethod { none | chap -chapsecret chap_secret } ] { [ -chapsecret chap_secret ] | [ -nochapsecret ] } [ -layer { replication | storage } ] [ -cacheprefetch { on | off } ] [ -localfcportmask port_mask ] [ -partnerfcportmask port_mask ] [ -hightempmode { on | off } ] [ -topology { standard | hyperswap } ] [ -vdiskprotectiontime value_in_minutes ] [ -vdiskprotectionenabled { yes | no } ] [ -odx { on | off } ] [ -easytieracceleration { on | off } ] [ -maxreplicationdelay value_in_seconds ] [ -partnershipexclusionthreshold value_in_seconds ]
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 Internet Small Computer System Interface
(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 the compression had been 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:
- -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:
- -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.
Thenochapsecret parameter cannot be specified whether
chapsecret is specified.
- -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 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).
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.
Remember: Setting a CHAP secret key for the system does not turn on
authentication for iSCSI hosts or remote copy partnerships. Remote
copy includes Metro Mirror, Global Mirror, and HyperSwap®. Turn off
authentication by issuing -iscsiauthmethod or
-rciauthmethod.
The
topology can only be set to
hyperswap only if node
sites have been configured. All nodes must have a site defined. If
both nodes are defined in an I/O group they must be assigned to the
same site (either
1 or
2;
3 cannot
be used for nodes). You must have at least one I/O group with both
nodes in site
1 and at least one I/O group with both
nodes in site
2.
Note: If there are any active relationships
defined, the system topology must be hyperswap.
An invocation
example
chsystem -ntpip 9.20.165.16
The
resulting output:
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An invocation example
to set up an external NTP server
chsystem -ntpip 123.234.123.234
The
resulting output:
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An
invocation example to change the preferred infocenterurl value
chsystem -infocenterurl http://miscserver.company.com/ibm/infocenter
The
resulting output:
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An
invocation example to change the local port mask value
To
set the local mask to sixty-two 0's and two 1's, indicating FC I/O
ports with IDs 1 and 2 are capable of local node communication:
chsystem -localfcportmask 11
The
resulting output:
No feedback
An
invocation example to change the partner port mask value
To
set the partner mask to sixty-three 0's and one 1, indicating that
FC I/O port with ID 2 is capable of remote node communication:
svctask chsystem -partnerfcportmask 0010
The
resulting output:
No feedback
An invocation example to change the HTM
chsystem -hightempmode on
The resulting output:
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An
invocation example to set the system topology
chsystem -topology standard
The resulting output:
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An invocation example to set authentication for
remote copy
chsystem -chapsecret ABCB1234 -iscsiauthmethod none -rcauthmethod chap
The resulting output:
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An invocation example to turn off volume protection
chsystem -vdiskprotectionenabled no
The resulting output:
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An invocation example to turn on volume protection and set the protection time to 60
minutes
chsystem -vdiskprotectionenabled yes -vdiskprotectiontime 60
The resulting output:
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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:
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An
invocation example to set the maximum replication delay
chsystem -maxreplicationdelay 100
The resulting output:
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An invocation example to set the partnership exclusion threshold
chsystem -partnershipexclusionthreshold 120
The resulting output:
No feedback