Expanding DRS-VOL capacity used in a Thin Image Advanced pair

Thin Image Advanced User Guide

Version

9.8.6

Audience

anonymous

Part Number

MK-98RD9033-00

You can expand the capacity of a DRS-VOL used only as a Thin Image Advanced pair volume. If you want to expand the DRS-VOL capacity when the Thin Image Advanced pair shares volumes with other replication software, see Expanding DP-VOL capacity when a Thin Image Advanced pair shares the same volume with other software.

You must have the Storage Administrator (Provisioning) role.
The LDEV format is not being performed on a DRS-VOL to be expanded.
A pool containing a DRS-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.
The following amount or number of resources do not exceed the maximum amount or number allowed on the storage system:
- Estimated Configurable in the Pools window
- Cache management devices

Calculating the amount or number of required resources

Amount of snapshot estimated manageable capacity (Estimated Configurable) required for expanding the capacity for a Thin Image Advanced pair

To expand the capacity for a Thin Image Advanced pair, verify that the snapshot estimated manageable capacity is available. Calculate the snapshot estimated manageable capacity required for expanding the capacity for a Thin Image Advanced pair using the following formula:

snapshot-estimated-manageable-capacity-for-Thin Image Advanced-volume-expansion 
= (root-volume-capacity-after-expansion – root-volume-capacity-before-expansion) x number-of-all-S-VOLs-under-the-root-volume 
< snapshot-estimated-manageable-capacity (Estimated Configurable)-in-the-Pools-window

Number of cache management devices

Calculate the number of cache management devices additionally required after capacity expansion by using the following formula:

number-of-cache-management-devices-additionally-required-after-expansion = ceiling ((root-volume-capacity-after-expansion 
– root-volume-capacity-before-expansion) / 2.99 TB) x 5 x number-of-all-S-VOLs-under-the-root-volume 
< remaining-number-of-cache-management-devices

In the calculation, 'ceiling' refers to rounding up the value enclosed in parentheses ( ) to the next integer. Note that, because this example shows a simplified estimation, the actual required number might be smaller than the estimated number.

To get remaining-number-of-cache-management-devices, subtract the number of cache management devices (displayed in the View Management Resource Usage window) in the storage system from the maximum number of cache management devices. For details, see Calculating the number of cache management devices.

Verify that all of the volumes used in Thin Image Advanced meet the prerequisites.
If the capacity of some volumes in a Thin Image Advanced pair can be expanded, while the capacity of other volumes cannot be expanded, the resync operation of the Thin Image Advanced pair cannot be performed after the expansion because the capacity of both the volumes is not the same.

If the resync operation of the Thin Image Advanced pair cannot be performed, complete the procedure refered to in Troubleshooting the expansion of Thin Image Advanced pair volume capacity.
Verify the pair statuses of the Thin Image Advanced pairs.
The Thin Image Advanced pair volume capacity can be expanded when the Thin Image Advanced pairs are in the PAIR, PSUS, or PSUE status. Verify the current pair statuses of the Thin Image Advanced pairs. If the pair statuses are not PAIR or PSUS, perform the pair operations, and then make sure that the pair statuses change to PAIR or PSUS.
Note: If the statuses remain PSUE or change to PSUE, this indicates an error condition.

If you expand the capacity of a P-VOL, verify that all pairs originating from the P-VOL are in the state in which the capacity can be expanded. If you expand the capacity of an S-VOL, verify that the pair having the snapshot data for which the S-VOL is assigned is in the state in which the capacity can be expanded.
Expand the P-VOL capacity used in the Thin Image Advanced pair.
- When using CCI, add the -request_id auto option to the raidcom extend ldev command to specify the asynchronous command processing. For example, to expand the capacity of LDEV#44:44 by 10GB:
```
raidcom extend ldev -ldev_id 0x4444 -capacity 10G –request_id auto
```
- When using HDvM - SN, expand the capacity in the Expand V-VOLs window.

Verify that expanding the P-VOL capacity used in the Thin Image Advanced pair is complete.

When using CCI, use the raidcom get command_status command to verify that the raidcom extend ldev command processing is complete, and then verify that the LDEV capacity is correct using the raidcom get ldev command. For example:

raidcom get command_status
HANDLE  SSB1  SSB2  ERR_CNT  Serial#  Description
00c3       -     -        0   500001  -

raidcom get ldev -ldev_id 0x4444 -fx
Serial#  : 500001
LDEV : 4444
SL : 0
CL : 0
VOL_TYPE : OPEN-V-CVS
VOL_Capacity(BLK) : 21073920
NUM_PORT : 0
PORTs :
F_POOLID : NONE
VOL_ATTR : CVS : QS : HDP : DRS
CMP : -
EXP_SPACE : -
B_POOLID : 5
LDEV_NAMING :
STS : NML
OPE_TYPE : NONE
OPE_RATE : 100
MP# : 0
SSID : 0005
Used_Block(BLK) : 0
FLA(MB) : Disable
RSV(MB) : 0
CSV_Status : ENABLED
CSV_PROGRESS(%) : -
CSV_Mode : COMPRESS
COMPRESSION_ACCELERATION : ENABLED
COMPRESSION_ACCELERATION_STATUS : ENABLED
CSV_PROCESS_MODE : INLINE
DEDUPLICATION_DATA : DISABLED
ALUA : Disable
RSGID : 0
PWSV_S : -
Snap_Used_Pool(MB) : 0
CL_MIG : N
SNAP_USED(MB) : -
SNAP_GARBAGE(MB) : -
DELETING_SNAP_GARBAGE : -
DELETING_SNAP_GARBAGE(%) : -

When using HDvM - SN, select Logical devices from the Storage Systems tree, and then display the LDEV tab. Verify that the capacity with the target LDEV number is correct.

Expand the S-VOL capacity of the Thin Image Advanced pair in the same way as the P-VOL capacity.
If the S-VOL capacity used in the Thin Image Advanced pair cannot be expanded, perform the procedure referring to Troubleshooting the expansion of Thin Image Advanced pair volume capacity.
Verify that expanding the S-VOL capacity used in the Thin Image Advanced pair is complete in the same way as the P-VOL capacity
Verify that the volume capacity used in the Thin Image Advanced pair is not being expanded.
- When using CCI, check if the P column in the result of the raidcom get snapshot command displays N. Following are examples of each command:
```
raidcom get snapshot -ldev_id 0x1000 -key detail -fx
SnapShot_name P/S   STAT Serial# LDEV# MU# P-LDEV# PID   % MODE 
SPLT-TIME SLU C_LDEV# P
ti            P-VOL PAIR  500001  1000   3    1100   5 100 ---- 
-         -         - N
```
  The P column displays whether the volume capacity is being expanded:
  - N: The volume capacity is not being expanded.
  - E: The volume capacity is being expanded. This status has been displayed for a while (30 seconds or so) after the expansion of the P-VOL or S-VOL capacity is complete, and then this status is changed to N.
- When using HDvM - SN, in the Local Replication window, select a P-VOL containing a volume to be expanded in the TI Root Volumes tab, and then click Operate TI Pairs. Check if the Processing Status field in the TI Pairs window is blank. (Expanding displays when the volume capacity is being expanded.) If the volume capacity is being expanded, wait until the expansion is complete, and then verify the status.