UNIX : Unmount FS, mount points, VG, release disks on AIX

I am using an older version of AIX for this, a 5.3 The current version is 7.2 I have renamed the servers for this tutorial

As usual, we will start with a request from customer to remove multiple FS and its VG, and release the disks back to SAN team

Please create a new CR for the removal of the following file systems, mount points and volume group from sushi01.
These were all used by the temporary SAP system CRC, we have now completed our upgrade testing in CRC and the SAN disk used needs to be unassigned and returned as free space.
I have already uninstalled the CRC SAP system and database, so all the file systems are empty and can simply be unmounted and removed.

We have a list of FS to be unmounted

Host : sushi01
Volume Group : crcvg
Mount point  File System Size
/db2/CRC  /dev/crclv 1 GB
/db2/CRC/log_dir  /dev/crclog_dirlv 20 GB
/db2/CRC/log_archive  /dev/crclogarchivelv 20 GB
/db2/CRC/log_retrieve  /dev/crcretrievelv 2 GB
/db2/CRC/saptemp1  /dev/crcsaptemp1lv 5 GB
/db2/CRC/sapdata1  /dev/crcsapdata1lv 160 GB
/db2/CRC/db2dump  /dev/crcdb2dumplv 2 GB
/db2/db2crc /dev/db2crclv 2.5 GB
/sapmnt/CRC  /dev/sapmntcrclv 8 GB
/usr/sap/CRC  /dev/usrsapcrclv 15 GB


And the removal of file systems

Host : sushi01
Volume Group : crcvg
Mount point File System Size
/db2/CRC /dev/crclv 1 GB
/db2/CRC/log_dir /dev/crclog_dirlv 20 GB
/db2/CRC/log_archive /dev/crclogarchivelv 20 GB
/db2/CRC/log_retrieve /dev/crcretrievelv 2 GB
/db2/CRC/saptemp1 /dev/crcsaptemp1lv 5 GB
/db2/CRC/sapdata1 /dev/crcsapdata1lv 160 GB
/db2/CRC/db2dump /dev/crcdb2dumplv 2 GB
/db2/db2crc /dev/db2crclv 2.5 GB
/sapmnt/CRC /dev/sapmntcrclv 8 GB
/usr/sap/CRC /dev/usrsapcrclv 15 GB

Since no one is using these file systems anymore, all I have to do is raise a Change Request, make the necessary mksysb system backup and go about my task

1. First we unmount the file systems

    #umount /db2/CRC 
    #umount /db2/CRC/log_dir 
    #umount /db2/CRC/log_archive 
    #umount /db2/CRC/log_retrieve 
    #umount /db2/CRC/saptemp1 
    #umount /db2/CRC/sapdata1 
    #umount /db2/CRC/db2dump 
    #umount /db2/db2crc 
    #umount /sapmnt/CRC 

    #umount /usr/sap/CRC 

2. Then we remove the VG from the server

    # varyoffvg crcvg

    # exportvg crcvg

3. Remove the disks used for this VG

    # rmdev -dl hdisk36
    # rmdev -dl hdisk77
    # rmdev -dl hdisk38
    # rmdev -dl hdisk39  
    # rmdev -dl hdisk40

    # rmdev -dl hdisk41  

4. Lastly I inform the SAN team of my work and to release the disks as free space