volume group

You can see how much disk space is allocated to rootvg with the lsvg command followed by the volume group name.

The only difference is, instead of the target filesystem residing in the same volume group, it would be created in a different volume group.

Logical volume management is a disk abstraction layer that allows you to group physical disks into a single entity called a volume group.

For best performance, use a volume group on the NIM master that does not contain the NIM resources being used for the AIX migration.

The LVM enables the data to be on multiple physical drives, though they might be configured to be on a single volume group.

It was now safe for me to remove the old disks from the volume group and remove them from the ODM.

You could export a volume group, use SAN replication to copy the data to a server on a remote site, and then import the volume group.

When you have your data ready to move, remove the volume group and its physical volumes from the source LPAR.

Above the physical volume (PV), three other cylinders are grouped by an ellipse showing how they together represent a volume group (VG).

Ensure the NIM client has a spare disk (not allocated to a volume group) large enough to contain a complete copy of its rootvg.

So after the assignment of PVs to the volume group, you can create a logical volume of any size (to the maximum of the VG size).

You can use the volume group export and import to refresh a database or to perform a disaster recovery test.

Let's look first at a volume group and find the logical volumes that are a part of it.

Now that I had my volume group, I was ready to create a logical volume.

Each of the disks in the volume group has management data, including a volume group descriptor area and a volume group status area.

global_pbuf_count: Reports back the number of pbufs that are added when a physical volume is added to any volume group.

On the standby node, it has access to the shared enhanced-concurrent volume group, but only in a passive, read-only mode.

Make sure to document Physical Volume Identification (PVID) numbers, volume group names, health check intervals, and any other tunables.

Finally, you actually tuned your logical volumes by determining and increasing the amount of pbufs used in a specific volume group.

Each logical volume is associated with a volume group, and each volume group typically contains several logical volumes.

And a volume group can be logically partitioned into logical volumes.

Each facet of the server should be evaluated, isolated, and put into its own volume group and type of storage.

At the operating system level, you can tune the characteristics for a volume group or even for individual physical volumes.

Once new disks have been added, you then can add these new physical volumes to your volume group(s) to create a fresh supply of extents.

Using this event producer, an application can verify the status of a Volume Group on the disk, with the LVM subsystem.

Different distros have different ways to determine whether the root filesystem path is or is not inside a volume group.

Before that screen (shown in Listing 6) is displayed, you will be required to choose a Volume Group in which to create the new file system.

That requires you to unmount the file systems that belong to the volume group you are going to export.

There's another, more obvious advantage to keeping data in its own volume group: performance.

With these changes finished, you should be able to extend the logical volumes in your volume group, as described shortly.

First, we identify the NetApp LUNs which will be used for the data volume group migration.

Volume group: Volume groups are required to be made highly available with many applications.

In the example environment, running lspv on the primary node confirms the shared volume group is in concurrent mode.

You may use the whole volume group for guided partitioning, or part of it.

A single AIX system might contain multiple resource groups, and there typically is one volume group defined per resource group.

This virtual disk, in LVM terms, is called volume group.

In this case, you will add a volume group since we don't have one defined at the moment.

The volume group name used to automatically partition using LVM is already in use.

This also makes the volume group active and updates the new LPAR with details of file systems associated with the logical volumes.

The LVM system will then allocate storage from the volume group we specify and create our new volume, which is now ready for use.

You can think of a volume group as a pool of storage that consists of one or more physical volumes.

The primary node has ownership of the shared volume group as it is varied-on and active.

One benefit of using the volume group export and import procedure is that it allows you to move data rather than copy it.

This VG has enough capacity to cater for a full copy of the NIM clients root volume group (rootvg).

When the file system contains all the data it requires, you can export the volume group from the source LPAR and import it on the target.

We booted the virtual machine and added the new disk to the volume group and formatted it for use.

The importvg command finds any remaining physical volumes belonging to the same volume group and includes them in the import.

All storage components of the DB2 database were defined on this volume group, including tablespaces, log, and backups.

It groups one or more physical volumes (disks) into a volume group.

From here, you can create a volume group, add to an existing volume group, or remove a volume from the LVM altogether.

The new instance is built from the running root volume group (similar to the alt_disk_install clone operation).

This command mirrors all the logical volumes that exist on a given volume group (see Listing 12).

You could import the volume group again on the source LPAR using importvg.

But maybe you do want to create a spare volume group on the source LPAR and create a file system and copy data to it.

The system automatically runs the varyonvg command to activate the volume group after it is imported.

Logical volume will be defined per volume group on one log; however, multiples might be defined.

You can check the volume group status by listing physical volumes with lspv. This shows the volume group name.

pv_pbuf_count: Reports back the number of pbufs added when a physical volume is added to the volume group.

Here, you're setting up a volume group named myvolgrp with host type LinuxSUSE, which defines attaching an Intel-based SUSE Linux OS.

This is a similar concept to AIX where you must make sure that your volume group is large enough to support this kind of operation.

Login with Admin1 user and able to create logical volumes under VG1 volume group.

We capture the current disk and volume group configuration with several LVM commands.

It is now safe to delete the physical volumes belonging to the volume group using rmdev.

This management data is stored on each physical volume of the volume group.

Multiple physical volumes make up a volume group.

Again, we also need to check the boot list and recreate the boot image for this now non-mirrored volume group.

Use the importvg command and a PhysicalVolume parameter to import the volume group.

You can't reduce paging space if you don't have enough space in your volume group for the temporary paging space.

A volume group is an aggregation of physical volumes.

Activate volume group AUTOMATICALLY yes at system restart?

Use the options in that menu to first create a volume group and then create your logical volumes inside it.

Remove the volume group and its disks from the source LPAR.

A modular approach to volume group layouts lets you keep rootvg disk usage small so it is easier to back up and recover.

It also passes the concerned disk name and volume group name in the DISK_NAME and VG_NAME fields.

After a WPAR is created, additional disks can be added to expand the rootvg volume group.

This means that any logical volumes I create from this volume group can be expanded and shrunk in 4 MB increments.

You can create new paging spaces in a data volume group, or a volume group just for paging.

After you initialize, choose Create new Volume Group to create a new volume group.

Each instance needs its own volume group.

Only the third, and lowest-volume, group of products and services is aimed at the local market.

The vgState event producer verifies the status of the Volume Group on a disk.

When you export a volume group, the whole volume group becomes unavailable until it is imported again.

Configure the disks, volume group, and file systems on the target LPAR.

Copying a filesystem data to a different volume group can be done using tar, cp, or cplv.

You can add more volumes to your volume group on the DS8000 for data or application usage.

When the problem exceeds the file system realm, it often goes to the volume group level.

Select the nodes appropriately to create a volume group.

To enable a shared volume group for enhanced concurrent mode (Fast Disk Takeover), you can use CSPOC.

This allows this server port access to all volumes in volume group myvolgrp.

This occurs if you are copying logical volumes to an empty volume group.

Figure 14 shows the logical volume, physical volume, file system, and volume group.

This new hdisk has been included in the existing root volume group (rootvg, also shown in Figure 8).

The LPAR has a single volume group, rootvg for the operating system, on a single disk.

Mirror the root volume group with the mirrorios command, if applicable.

Search for the host and Identify Volume Group.

Create a volume group and logical volume to hold the client's rootvg.

A single volume group (VG) was created that spanned all eight volumes.

The selected volume group could not be deleted.

The logical volumes in the shared volume group are closed.

vgreduce removes unallocated PVs from a volume group, reducing the VG.

Ensure that this file system and the volume group (for example, rootvg) has adequate space available.

Whatever sort of disks they are, you need to make them available to the target LPAR before you can do the import of the volume group.

Moving on to the technical side of LPAR migrations, the first thing you must manage is the root volume group (rootvg).

The logical volumes in the shared volume group are open.

You only need to specify one physical volume, even if there are several physical volumes in the volume group.

With the correct disks identified (hdisk12 and 13), I could add these disks (with extendvg) to the existing data volume group (datavg).

Keep some spare disk for paging, either in rootvg or another volume group.

I tried extendvg and mirrorvg to create another copy of the volume group on another disk.

These disks are collected in a group, called the volume group.

The volume group is shown as None, and the volume group status doesn't display as active.

You can slice off an entire volume group from an AIX system with the exportvg command.

Record Volume Group ID V77 in this example for future reference.

You can add a volume group or add logical volumes.

Next, we create logical volumes in the volume group "hbvg" .

It is a regular JFS2 file system in a regular volume group.

First, let's see what disks are in the root volume group (see Listing 8).

In the example in Figure 2, a volume group named LV0 was created, leaving some free-space for other LVs (or for posterior LV0 growth).

lsvg is the command that provides volume group information (see Listing 4).

In our case we created the logical volumes per volume group.

Varyon the volume group and disable auto start at mount.

Use the chhostconnect dscli command to add the created volume group to the new host.

How do I know if my volume group is normal, big, or scalable?

Again, we use extendvg to add the NetApp disks to the data volume group (datavg).

If not, is the volume group accessible with lsvg or varyonvg, or has it lost quorum?

Then we mirror the volume group with the new hdisk.

In this step, I create a volume named mysuseboot in extent pool p2 and assign it to volume group v35.

While LVM is running, we can add physical volumes to the volume group or even remove them.

We can specify the particular extent size to use at volume group creation time.

Run the lsvg command on the volume group and look at the value for MAX PVs.

We mirror the volume group from the DS8300 disk (hdisk2) to the new NetApp disk (hdisk12).

For the DB2 instance db2admin, we will use volume group vgA and for the DB2 instance db2adma the volume group vgB.

How do I display all logical volumes that are part of a volume group (for example, rootvg)?

How to add a disk to a volume group?

AIX 5L Version 5. 3 has introduced a new VG type called scalable volume group (scalable VG).

The new instance is housed within the current root volume group (for example, the same disks).

On the NIM master, I have created a new volume group (VG) named nimadmvg.

Let's display your lvmo tunables for the data2vg volume group (see Listing 11).

The value is 32 for normal, 128 for big, and 1024 for scalable volume group.

You need to bring hdisk1 into the root volume group (see Listing 10).

How to create a volume group?

Now we can remove the DS8300 hdisks from the data volume group using reducevg and remove the disk from the ODM.

Imagine the following situation: You have a volume group with two 80GB disks, and you want to upgrade those to 160GB disks.

Copying a logical volume to a different volume group

Next, increase the logical volume within this volume group. You can verify with lvdisplay by comparing the LV Size row

Using this standard, the volume group name consists of exactly 12 characters with the following structure

Volume group descriptor area and volume group status area

You should now be able to export the volume group using exportvg

Support for minor numbers greater than 512 in a volume group

default mass storage volume group

You use the following command to change the characteristics of a volume group

Not enough available space in the volume group

Multiple instances of AIX on a single root volume group (multibos)

Let's look at how to copy a logical volume to a different volume group. The steps involved are

Remove a volume group from the source LPAR

Let's increase the pbuf count for this volume group

List file systems in the volume group

To create volume group using C-SPOC

In short, there are three steps to moving a volume group

Unmount any file systems in the volume group using the umount command

d is the hdisk name for the alternate root volume group (altinst_rootvg)

You can make the volume group inactive with the varyoffvg command