Search <book_title>...

Storage Foundation Cluster File System High Availability 7.2 Administrator's Guide - Solaris

Last Published: 2018-03-06

Product(s): InfoScale & Storage Foundation (7.2)

Platform: Solaris

Migrating to thin provisioning

The SmartMove™ feature enables migration from traditional LUNs to thinly provisioned LUNs, removing unused space in the process.

To migrate to thin provisioning

Check if the SmartMove feature is enabled.
```
# vxdefault list
KEYWORD                        CURRENT-VALUE   DEFAULT-VALUE  
usefssmartmove                 all             all       
...
```
If the output shows that the current value is none, configure SmartMove for all disks or thin disks.
See Configuring SmartMove .
Add the new, thin LUNs to the existing disk group. Enter the following commands:
```
# vxdisksetup -i da_name
# vxdg -g datadg adddisk da_name
```
where da_name is the disk access name in VxVM.
To identify LUNs with the thinonly or thinrclm attributes, enter:
```
# vxdisk -o thin list
```

Add the new, thin LUNs as a new plex to the volume. On a thin LUN, when you create a mirrored volume or add a mirror to an existing LUN, VxVM creates a Data Change Object (DCO) by default. The DCO helps prevent the thin LUN from becoming thick, by eliminating the need for full resynchronization of the mirror.

NOTE: The VxFS file system must be mounted to get the benefits of the SmartMove feature.

The following methods are available to add the LUNs:

Use the default settings for the vxassist command:
```
# vxassist -g datadg mirror datavol da_name
```

Specify the vxassist command options for faster completion. The -b option copies blocks in the background. The following command improves I/O throughput:

# vxassist -b -oiosize=1m -t thinmig -g datadg mirror \
  datavol da_name

To view the status of the command, use the vxtask command:

# vxtask list
TASKID PTID TYPE/STATE    PCT   PROGRESS
211         ATCOPY/R 10.64% 0/20971520/2232320 PLXATT vol1 vol1-02 xivdg smartmove
212         ATCOPY/R 09.88% 0/20971520/2072576 PLXATT vol1 vol1-03 xivdg smartmove
219         ATCOPY/R 00.27% 0/20971520/57344 PLXATT vol1 vol1-04 xivdg smartmove

# vxtask monitor 211  
TASKID PTID TYPE/STATE    PCT   PROGRESS
211         ATCOPY/R 50.00% 0/20971520/10485760 PLXATT vol1 vol1-02 xivdg smartmove
211         ATCOPY/R 50.02% 0/20971520/10489856 PLXATT vol1 vol1-02 xivdg smartmove
211         ATCOPY/R 50.04% 0/20971520/10493952 PLXATT vol1 vol1-02 xivdg smartmove
211         ATCOPY/R 50.06% 0/20971520/10498048 PLXATT vol1 vol1-02 xivdg smartmove
211         ATCOPY/R 50.08% 0/20971520/10502144 PLXATT vol1 vol1-02 xivdg smartmove
211         ATCOPY/R 50.10% 0/20971520/10506240 PLXATT vol1 vol1-02 xivdg smartmove

Specify the vxassist command options to reduce the effect on system performance. The following command takes longer to complete:
```
# vxassist -oslow -g datadg mirror datavol da_name
```

Optionally, test the performance of the new LUNs before removing the old LUNs.

To test the performance, use the following steps:

Determine which plex corresponds to the thin LUNs:

# vxprint -g datadg

TY NAME         	     ASSOC   	       KSTATE   LENGTH     PLOFFS  STATE     TUTIL0 PUTIL0
dg datadg       	     datadg      	   -        -          -       -         -       -
dm THINARRAY0_02      THINARRAY0_02   -      	 83886080   -       -         -       -
dm STDARRAY1_01	      STDARRAY1_01    -  	     41943040   -       -OHOTUSE  -       -

v  datavol      	     fsgen        	  ENABLED 	41943040   -       ACTIVE    -       -
pl datavol-01   	     datavol      	  ENABLED 	41943040   -       ACTIVE    -       -
sd STDARRAY1_01-01    datavol-01   	  ENABLED 	41943040   0       -         -       -
pl datavol-02   	     datavol      	  ENABLED 	41943040   -       ACTIVE    -       -
sd THINARRAY0_02-01   datavol-02   	  ENABLED 	41943040   0       -         -       -

The example output indicates that the thin LUN corresponds to plex datavol-02.

Direct all reads to come from those LUNs:

# vxvol -g datadg rdpol prefer datavol datavol-02

Remove the original non-thin LUNs.
Note:
The ! character is a special character in some shells. This example shows how to escape it in a bash shell.
```
# vxassist -g datadg remove mirror datavol \!STDARRAY1_01
# vxdg -g datadg rmdisk STDARRAY1_01
# vxdisk rm STDARRAY1_01
```
Grow the file system and volume to use all of the larger thin LUN:
```
# vxresize -g datadg -x datavol 40g da_name
```