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 [ -namesystem_name ] [ -speedfabric_speed ] [ -aliasid_alias ] [ -icatipicat_console_ip_address ] [ -invemailintervalinterval ] [ -gmlinktolerancelink_tolerance ] [ -gmmaxhostdelaymax_host_delay ] [ -gminterdelaysimulationinter_system_delay_simulation ] [ -gmintradelaysimulationintra_system_delay_simulation ] [ -icatipipv4_icat_ip_address ] [ -icatip_6ipv6_icat_ip_address ] [ -ntpipipv4_ntp_ip_address ] [ -ntpip_6ipv6_ntp_ip_address ] [ -isnsipsns_server_address ] [ -isnsip_6ipv6_sns_server_address ] [ -relationshipbandwidthlimitbandwidth_in_mBps ] [ -infocenterurlurl ] [ -iscsiauthmethod { none | chap -chapsecretchap_secret } ] [ -rcauthmethod { none | chap -chapsecretchap_secret } ] { [ -chapsecretchap_secret ] | [ -nochapsecret ] } [ -layer { replication | storage } ] [ -cacheprefetch { on | off } ] [ -localfcportmaskport_mask ] [ -partnerfcportmaskport_mask ] [ -topology { standard | hyperswap } ] [ -vdiskprotectiontimevalue_in_minutes ] [ -vdiskprotectionenabled { yes | no } ] [ -odx { on | off } ] [ -easytieracceleration { on | off } ] [ -maxreplicationdelay ]
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.
- -speedfabric_speed
- (Optional) Specifies the speed of the fabric to which this system
is attached. Valid values are 1 or 2 (GB).
Attention: Changing the speed on a running system breaks input
or output (I/O) service to the attached hosts. Before changing the
fabric speed, stop I/O from active hosts and force these hosts to
flush any cached data by unmounting volumes (for UNIX host types) or by removing drive letters
(for Windows host types).
Some hosts might need to be rebooted to detect the new fabric speed.
- -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.
- -gminterdelaysimulationinter_system_delay_simulation
- (Optional) Specifies the intersystem
delay simulation, which simulates the Global Mirror round trip delay
between two systems, in milliseconds. The default is 0.
The valid range is 0 to 250 milliseconds.
- -gmintradelaysimulationintra_system_delay_simulation
- (Optional) Specifies the intrasystem
delay simulation, which simulates the Global Mirror round trip delay
in milliseconds. The default is 0. The valid range
is 0 to 250 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. 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.
- -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.
- -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.
- -maxreplicationdelay
- (Optional) Sets a maximum replication delay in seconds. The value
must be a number from 0 to 360.
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:
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
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 set the system topology
chsystem -topology standard
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