Use the chfcmap command to modify attributes
of an existing mapping.
Syntax
chfcmap
[ -name new_name_arg
] { fc_map_id | fc_map_name
}
chfcmap
{ [ -consistgrp
{ consist_group_id
| consist_group_name } ]
| [ -force ]
} [ -copyrate rate
] [ -autodelete { on | off }
] [ -cleanrate
{ rate
} ] {
fc_map_id | fc_map_name
}
Parameters
- -namenew_name_arg
- (Optional) Specifies the new name to assign to the
mapping. The -name parameter cannot be used
with any other optional parameters.
- -force
- (Optional) Specifies
that the mapping be modified to a stand-alone mapping (equivalent
to creating the mapping without a consistency group ID). You cannot
specify the -force parameter with the -consistgrp parameter.
Important: Using the
force parameter might result in a loss of access. Use it only under
the direction of your product support information.
- -consistgrpconsist_group_id
| consist_group_name
- (Optional) Specifies the
consistency group for which you want to modify the mapping. You cannot
specify the -consistgrp parameter with the -force parameter.
Note: The consistency group cannot be
modified if the specified consistency group is in the preparing, prepared, copying, suspended, or stopping.
- -copyraterate
- (Optional) Specifies the copy rate. The rate value can be 0 - 150. The default value is 50. A value of 0 indicates no background
copy process. For the supported -copyrate values
and their corresponding rates, see Table 1.
- -autodeleteon | off
- (Optional) Specifies that the autodelete function
be turned on or off for the specified mapping. When you specify the -autodelete on parameter, you are deleting a mapping after the background copy completes. If the background copy
is already complete, the mapping is deleted immediately.
- -cleanraterate
- (Optional) Sets the cleaning
rate for the mapping. The rate value can be 0 - 150. The default value is 50.
- fc_map_id | fc_map_name
- (Required) Specifies the ID or name of the mapping to modify. Enter
the ID or name last on the command line.
Description
The chfcmap command modifies attributes
of an existing mapping.
Attention: You must enter
the fc_map_id | fc_map_name last on the command
line.
If you have created several FlashCopy mappings for
a group of volumes that contain elements of data for the same application,
you can assign these mappings to a single FlashCopy consistency
group. You can then issue a single prepare command and a single
start command for the whole group, for example, so that all
of the files for a particular database are copied at the same
time.
The -copyrate parameter specifies
the copy rate. If 0 is specified, background copy
is disabled. The -cleanrate parameter specifies
the rate for cleaning the target volume. The cleaning process is only
active if the mapping is in the copying state and the background copy has completed, the mapping is in the copying state and the background copy is disabled,
or the mapping is in the stopping state.
You can disable cleaning when the mapping is in the copying state by setting the -cleanrate parameter to 0. If the -cleanrate is set to 0, the cleaning process runs at the default
rate of 50 when the mapping is in the stopping state to ensure that the stop operation completes.
This table provides the relationship of the copy rate and cleaning rate values to the attempted number
of grains to be split per second. A grain is the unit of data represented
by a single bit.
Table 1. Relationship between the cleaning rate,
data rate, and grains per second values
| User-specified cleaning rate attribute value |
Data copied/sec |
256 KB grains/sec |
64 KB grains/sec |
| 1 - 10 |
128 KB |
0.5 |
2 |
| 11 - 20 |
256 KB |
1 |
4 |
| 21 - 30 |
512 KB |
2 |
8 |
| 31 - 40 |
1 MB |
4 |
16 |
| 41 - 50 |
2 MB |
8 |
32 |
| 51 - 60 |
4 MB |
16 |
64 |
| 61 - 70 |
8 MB |
32 |
128 |
| 71 - 80 |
16 MB |
64 |
256 |
| 81 - 90 |
32 MB |
128 |
512 |
| 91 - 100 |
64 MB |
256 |
1024 |
| 101 - 110 |
128 MB |
512 |
2048 |
| 111 - 120 |
256 MB |
1024 |
4096 |
| 121 - 130 |
512 MB |
2048 |
8192 |
| 131 - 140 |
1 GB |
4096 |
16384 |
| 141 - 150 |
2 GB |
8192 |
32768 |
Note: Maps that are rc_controlled are
not shown in the view when this command is specified.
An invocation example
chfcmap -name testmap 1
The resulting output:
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