Use the Modifying FlashCopy® Mapping
panel in
the SAN Volume Controller Console to
change attributes of a select FlashCopy mapping.
Attributes
The
following attributes are displayed in the table:
- FlashCopy Name
- Displays the name
of the FlashCopy mapping.
- FlashCopy ID
- Displays the ID of
this mapping.
- Consistency Group
- Displays
the name of the consistency group for this
mapping if this mapping is a member of a group. If you specified the
consistency group to be deleted automatically when it is empty, the
consistency group is displayed with (autodelete) behind
the name. A consistency group without automatic deletion specified
is displayed with (non autodelete) behind the
name.
- Cleaning Rate
- Displays
the current cleaning rate.
- Copy
Rate
- Displays the current copy rate for this
mapping.
The value shown can be either a number 1 - 100 to indicate the copy
rate (a higher number indicates a faster copy rate) or NOCOPY,
which disables the copy. The default value is 50 (2 MB per second).
The following table shows the relationship of
the copy and cleaning rate value 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 rate,
data rate and grains per second values| User-specified 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 |
- Automatically
Delete
- Indicates whether the FlashCopy mapping
is deleted
when the copy completes. The following values are possible:
- Enabled
- Indicates that the cluster supports the automatic
deletion of FlashCopy mapping when it is done copying.
- Disabled
- Indicates
that the cluster supports the automatic
deletion of FlashCopy mapping when it is done copying;
however, the function is turned off.
Fields
- New Name
- Enter a new name for the FlashCopy mapping.
- Consistency Group
- Select a consistency
group to contain the mapping. A consistency
group is a groups of mappings that can be started at the same time.
This enables multiple virtual disks to be copied at the same time,
which creates a consistent copy of multiple disks.
- Copy Rate (NOCOPY is the lowest
rate)
- Select the copy rate for this mapping. You
can select a number 1 - 100 to indicate the
copy rate (a higher number indicates a faster copy rate) or NOCOPY,
where the copy process is disabled. The default value is 50 (2 MB
per second).
The following table shows the relationship of
the copy and cleaning rate value to the attempted number of grains
to be split per second. A grain is the unit of data represented by
a single bit.
Table 2. Relationship between the rate,
data rate and grains per second values| User-specified 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 |
The data copied per second and the
grains per second numbers represent standards that the SAN Volume
Controller tries to achieve. The SAN Volume Controller is unable to
achieve these standards if insufficient bandwidth is available from
the nodes to the physical disks that make up the managed disks (MDisks)
after taking into account the requirements of foreground I/O. If this
situation occurs, background copy I/O contends for resources on an
equal basis with I/O that arrives from hosts. Both tend to see an
increase in latency and consequential reduction in throughput with
respect to the situation had the bandwidth not been limited.
- Cleaning Rate (NOCLEAN is the
lowest rate)
- Select the cleaning rate for this mapping. The
value NOCLEAN is
the lowest rate and 100 is the highest. See Table 1 for details.
- Automatically delete mapping when
the background copy completes
- Check this box
to automatically delete a FlashCopy mapping after the
background
copy has completed. If the background copy has already completed,
this mapping is automatically deleted.
Actions
The
following actions are available:
- OK
- Click
this button to change the selected FlashCopy mapping.
- Cancel
- Click this button to exit the
panel without changing the selected FlashCopy mapping.