How To Remove VG With No Disk?

How to remove VG with no disk?

Or

How to remove VGDA or VG information?

VGDA information is mostly available in /etc/filesystem and ODM.

Command to remove VGDA information:

Run the command,

# exportvg

This command will remove vg information from /etc/filesystem and ODM.

And this will only happen when VG is not varied on.

Command to check whether the VG is varied on or not:

# lsvg –o | lsvg –il

Command to vary off a VG:

# varyoff vg <vgname>

Happy learning !

Steps To Create A VG With User Defined Name

Steps To Create A VG With User Defined Name

This Blogpost deals about steps to create a VG with user defined name. Initially we discussed about how to create a VG with default name.

End users in an environment sometimes require VG LV creation with a defined name as per requirement. In this case, users cannot rely on default naming provided by the OS.

The various commands used in creating a VG and LV with user defined name will be discussed here in this particular post.

Check the PV information by running:

# lspv

Create a VG with user defined name “oracle_vg” (for eg) by running the following command:

# mkvg –y oracle_vg –S 32 hdisk0 hdisk5

Interpretation for the above command:

# mkvg –y vgname –S (for scalable), -N (for Normal), -B (for Big) <PP size> PV

Admin can verify the VG information by running the following commands:

# lsvg

OR

# lsvg oracle_vg

OR

# lsvg –p oracle_vg

Once a VG is created, a LV with user defined name (oracle_lv) is created on top of it by running the following command:

# mklv –y oracle_lv –t jfs/jfs2 oracle_vg 10 hdisk5

Interpretation for the above command:

# mklv –y lvname –t <type of LV> <vgname> <Number of LPs> PV

Admin can verify the LV creation by running:

# lslv oracle_lv

OR

# lslv –l oracle_lv

Next Step is to create a directory:

# mkdir /ora

Then create a FS on oracle_lv with /ora as mount directory:

# crfs –v jfs/jfs2 –d oracle_lv –m /ora –A yes

Now Mount the FS:

# mount /ora

Verify the FS:

# mount

Complete FS information:

# lsfs

Complete PV, VG information:

# Lsvg –o | lsvg –il

Next, I will discuss Steps to increase/decrease size of a FS.

Happy Learning !

Steps To Create A File System

This post deals about the various steps involved in creating a file system.

Once a PV is available in the system, admin can list down the PVs by running the following command:

# lspv

lspv command

To Create a VG from a PV with Default Name, command used is:

# mkvg hdisk0

This command will create a VG with default name vg00.

Once a VG is created, LV is created with a default name lv00 and admin assigns number of LPs to the LV by running the following command:

# mklv vg00 10

To Check VG information interms of PPs assigned, command used:

# lsvg -p vg00

lsvg command

To Check VG information interms of LPs assigned, command used:

# lsvg -l vg00

lsvg -l

To Check complete LV information, command used:

# lslv lv00

OR

# lsvg -l  vg00

After LV creation, a directory is created:

# mkdir /test01

After the creation of Directory, a FS is created by running the following command:

# crfs -v jfs -d lv00 -m /test01 -A yes

CRFS stands for create a File System.

-v flag is used to mention the type of file system admin is planning to create.

-d is used to know in which LV the file system will be created and -m for the directory on which the file system will be mounted.

- A flag is used to Activate the FS on Next Reboot.

P.S : there are 2 commands to create a FS:

1. crfs

2. mkfs

The only difference between the two is, mkfs only creates a file system whereas crfs not only creates a FS in LV, it also mounts the FS on a  directory and updates /etc/filesystem and ODM about the FS created.

A File System created using crfs command will have the same name as that of the directory. here /test01.

Next, admin mounts the FS by running:

# mount /test01

Verifies the FS is mounted or not:

# mount

To Display Complete FS information, command used is:

# df -m

OR

# lsfs

lsfs command

Finally, we can check the complete information about PV, VG, LV and FS by running the following command:

# lsvg -o | lsvg -il

This post gave an insight on how a FS is created by creating a VG and LV first on a PV.

keep reading to know how unmounting is done and how a VG is created with a user defined name.

till then, Happy Learning !