You can expand the capacity of DP-VOLs used as pair volumes when a TC pair is used with HTI. This procedure provides an
example for expanding the DP-VOL capacity in a configuration where the HTI L1 pair and L2 pair are
created for each volume of the P-VOL and S-VOL in the TC pair. For the detailed
procedures for verifying the differential data management method, expanding the
capacity, and verifying the expansion during the following procedure, see Expanding DP-VOL
capacity used in TrueCopy
pair .
- A V-VOL to be expanded is not an external volume.
- The LDEV format is being performed on a V-VOL to be expanded.
- A pool containing a V-VOL to be expanded meets any of the following
conditions:
- Normal condition
- The used capacity of the pool does not exceed the threshold
- The pool is not being shrunk
- When using GAD, TC,
or UR, make
sure that there is enough software license capacity for the page capacity
assigned to the expanded volume capacity before the expansion.
- A V-VOL to be expanded is created on a valid storage system. See
Expanding DP-VOL
capacity while keeping pair status.
- A V-Vol to be expanded is not used in a pair with the clone
attribute.
- Ensure that the following numbers required after the expansion do
not exceed the maximum number allowed on the storage system:
- The snapshot estimated manageable capacity
- The number of cache management devices
- The subscription limit of the V-VOL capacity
- If a TC pair is used with
Thin Image Advanced, ensure
that the following numbers do not exceed the maximum number allowed on the
storage system:
- Estimated Configurable in Pools window
- Number of cache management devices
For information about calculating these numbers, see Calculating the snapshot estimated manageable
capacity, the numbers of cache management devices, and the subscription limit of
the V-VOL capacity.
-
Verify that each volume of the P-VOLs and S-VOLs in a TC pair and HTI pairs with which the
TC pair shares the
same volumes meets the prerequisites.
-
Display the detailed information about the TC pair on CCI.
Verify whether the current differential data management method is
the SM difference management or the hierarchical difference management by a
drive.
- If the SM difference management is applied, proceed to step
3.
- If the hierarchical difference management is applied,
proceed to step 4.
- If using HDvM - SN, verify the advanced system settings No.5 and No.6.
- If both the advanced system settings No.5 and No. 6
are set to Disable, the SM difference
management is applied. Go to Step 3.
- If either or both the advanced system settings No.5
and No.6 are set to Enable, the
hierarchical difference management is applied. Go to Step
4.
-
Change the differential data management method to the hierarchical difference
management.
-
Change system settings for hierarchical difference management.
- If using CCI, set the system option mode (SOM) 1198 to ON
and 1199 to OFF by using the raidcom modify
system_opt command.
Command
example:
raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
- If using HDvM - SN, set the advanced system settings No. 5
to Enable and No.6 to
Disable in the Edit Advanced System Settings window.
-
Suspend the TC
pair.
-
Resynchronize the TC pair.
-
Display the detailed information about the TC pair on CCI,
and then verify that the current differential data management method is
the hierarchical difference management.
-
Suspend the TC
pair.
-
Verify the pair statuses of the HTI pairs.
The HTI pair volume
capacity can be expanded when the HTI pairs are in the PAIR, PSUS or PSUE status. Verify the
current pair statuses of the HTI pairs. If the pair statuses are not PAIR, PSUS or PSUE,
perform the pair operations, and then make sure that the pair statuses are
migrated to PAIR or PSUS.
-
Expand each volume capacity, and then verify that the expansion is complete in
the expansion order shown in the following figure.
-
Resynchronize the TC
pair.
-
Verify that both the pair statuses of the P-VOL and S-VOL in each pair of the
TC pair have changed
to PAIR.
In addition, verify that each volume capacity in the
TC pair and
HTI pair is not being
expanded.
The following table shows how the expansion process
is displayed.
Expansion status |
CCI |
HDvM - SN |
P column in the pairdisplay or
raidcom get snapshot command |
Processing Status field in the Remote Replication or HTI pairs
window |
Not being expanded |
N |
Blank |
Being expanded |
E* |
Expanding* |
* This status has been displayed after
expanding the P-VOL or S-VOL capacity in the TC pair,
and before performing the pair resync operation. After the
resync operation is complete, the status is migrated to the
Not being expanded status. In the HTI pair,
the Being expanded status is displayed for a while (30
seconds or so) after the expansion of the P-VOL and S-VOL
capacity is complete. After that, the status is migrated to
the Not being expanded status. |