Migrate VxVM boot disks to higher capacity disk

Hi, Im getting a downtime of 4 hrs to do porting of bootdisks.
Currently, the system is running on Sf4800. 2 internal disk 36G connected to a SE3510 storage.
We're getting 72G disks and we want to restore the OS from the current 36G to the 72G disk. System is under veritas volume manager ctrl. Any steps provided would help. Thanks.

config as follows:
Filesystem kbytes used avail capacity Mounted on
/dev/vx/dsk/bootdg/rootvol 20160418 10366246 9592568 52% /
/devices 0 0 0 0% /devices
ctfs 0 0 0 0% /system/contract
proc 0 0 0 0% /proc
mnttab 0 0 0 0% /etc/mnttab
swap 12996192 1680 12994512 1% /etc/svc/volatile
objfs 0 0 0 0% /system/object
/platform/sun4u-us3/lib/libc_psr/libc_psr_hwcap1.so.1 20160418 10366246 9592568 52% /platform/sun4u-us3/lib/libc_psr.so.1
/platform/sun4u-us3/lib/sparcv9/libc_psr/libc_psr_hwcap1.so.1 20160418 10366246 9592568 52% /platform/sun4u-us3/lib/sparcv9/libc_psr.so.1
fd 0 0 0 0% /dev/fd
swap 17245824 4251320 12994504 25% /tmp
swap 12994640 136 12994504 1% /var/run
swap 12994504 0 12994504 0% /dev/vx/dmp
swap 12994504 0 12994504 0% /dev/vx/rdmp
/dev/vx/dsk/ssdc/export 30720000 8094698 21211284 28% /export
/dev/vx/dsk/ssdc/upgrade 8396800 3302443 4776025 41% /ocs/upgrade
/ocs/ericsson 30720000 17607384 12306679 59% /var/opt/ericsson
/ocs/3pp/opt/borland 9216000 5421853 3557468 61% /opt/borland
/ocs/3pp/opt/sybase 9216000 5421853 3557468 61% /opt/sybase
/ocs/3pp/opt/sun 9216000 5421853 3557468 61% /opt/sun
/ocs/3pp/opt/versant 9216000 5421853 3557468 61% /opt/versant
/export/opt/ericsson 30720000 8094698 21211284 28% /opt/ericsson

Searching for disks...done

AVAILABLE DISK SELECTIONS:
0. c0t0d0 <HITACHI-DK32EJ36NSUN36G-PQ0F cyl 24620 alt 2 hd 27 sec 107>
/ssm@0,0/pci@18,700000/pci@1/SUNW,isptwo@4/sd@0,0
1. c1t40d0 <SUN-StorEdge3510-415G cyl 65533 alt 2 hd 64 sec 340>
/ssm@0,0/pci@19,700000/SUNW,qlc@2/fp@0,0/ssd@w216000c0ff882692,0
2. c2t0d0 <SUN36G cyl 24620 alt 2 hd 27 sec 107>
/ssm@0,0/pci@1c,700000/pci@1/SUNW,isptwo@4/sd@0,0
3. c3t40d0 <SUN-StorEdge3510-415G cyl 65533 alt 2 hd 64 sec 340>
/ssm@0,0/pci@1d,700000/SUNW,qlc@2/fp@0,0/ssd@w216000c0ff882638,0

DEVICE TYPE DISK GROUP STATUS OS_NATIVE_NAME
c0t0d0s2 auto rootdisk rootdg online c0t0d0s2
c1t40d0s2 auto disk2mirr ssdc online c1t40d0s2
c2t0d0s2 auto rootmirr rootdg online c2t0d0s2
c3t40d0s2 auto disk2 ssdc online c3t40d0s2

rootdg enabled 1215624401.12.cnoss1
ssdc enabled 1215570882.12.cnoss1

#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/vx/dsk/bootdg/swapvol - - swap - no nologging
/dev/vx/dsk/bootdg/rootvol /dev/vx/rdsk/bootdg/rootvol / ufs 1 no nologging
/devices - /devices devfs - no -
ctfs - /system/contract ctfs - no -
objfs - /system/object objfs - no -
swap - /tmp tmpfs - yes -
#NOTE: volume rootvol () encapsulated partition c0t0d0s0
#NOTE: volume swapvol () encapsulated partition c0t0d0s1
/dev/vx/dsk/ssdc/export /dev/vx/rdsk/ssdc/export /export vxfs 3 yes -
/dev/vx/dsk/ssdc/3pp /dev/vx/rdsk/ssdc/3pp /ocs/3pp vxfs 3 yes -
/dev/vx/dsk/ssdc/swap - - swap - no nologging
#NOTE: volume rootvol () encapsulated partition c0t0d0s0
#NOTE: volume swapvol () encapsulated partition c0t0d0s1

won't a flash archiv work out for you?

Nope. we won't be using flash archive

Can you please check if the below steps are correct and if changes are need to be made further?

-Full OS backup is to be taken prior to activity
-Make a backup copy of /etc/vfstab file, comment out ossdg entries
-Identify the rootmirror disk using format
-set system eeprom to auto-boot false,
#eeprom auto-boot?=false
then
init 0 to bring system to ok> prompt
pull out the SE3510 FC connection cables

• Pull out rootmirror 36G HDD and insert 72G HDD
  -Boot up the system using the rootdisk
• format new drive and label disk with appropriate partition sizing
  (need confirmation from Ericson)

-newfs on the filesystems on the new 72G HDD
Newfs /dev/rdsk/c2t0d0s0

• mount root slice from the new HDD to a temp mount point
  Mkdir /s0
  Mount /dev/rdsk/c2t0d0s0 /s0
• perform ufsdump / ufsrestore for root partition
  Ufsdump 0f - / | (cd /s0; ufsrestore rf -)
  -when root partition is done with restoration, perform installboot bootblk on new disk

Cd /usr/platform/`uname -i`/lib/fs/ufs
Installboot bootblk /dev/rdsk/c2t0d0s0
Backup /etc/system file and /etc/vfstab
Touch /s0/etc/vx/reconfig.d/state.d/install-db
Vi /s0/etc/system :-(remove all rootdev statements)
Cp /s0/etc/vfstab.prevm /s0/etc/vfstab

• umount and remove the temp dirs created at step6
  Umount /s0

• bring the system down to ok> prompt -> poweroff
  -swap in new HDD to primary controller
  -plug in FC cables

• boot the system to single user, check vfstab entries and clear filesystem errors (if any), format and check the cxtxdx
  -replace the backup vfstab file with ossdg entries

• boot the system to multi-user
  #vxiod set 10
  #vxconfigd -m disable -k
  #/usr/lib/vxvm/bin/vxencap rootdisk=c0t0d0
  #init 0
  Ok> boot
  Verify using vxdisk list, vxdg list if the status is ok.

• slot in 2nd new HDD to secondary controller, make sure OS detects the disk, label the disk.
  Devfsadm -C
  #vxdctl enable
  -use vxdiskadm -> choose option 4 (ensure VM detects as rootmirror not found) choose option 5 (to sync the rootmirror disk)
  -vxtask list (monitor disk synchronization to complete)

Anyone here to confirm the steps are right pls?