Veritas Volume Manager FAQ

1) Installing Veritas Volume Manager ?

Veritas Volume Manager is also called (VVM or VxVM )

Features :
1) VVM is Available for - Windows. Linux, HP-UX, Solaris, AIX.
2) Versions (3.1, 3.2, 3.5, 4.0, 4.1, 5.0).

Installing Veritas Volume Manager

1. Insert the Veritas volume manager software cdrom into
   the cdrom drive. If volume management is enabled, it will
   automatically mount to /cdrom/volume_manager3.5
   (depending on the precise release iteration, the exact path
   may differ in your case):

2. Change to the directory containing the Veritas Volume Manager packages:
   # cd /cdrom/volume_manager3.5/pkgs

3. Add the required packages.
   Note that the order specified is
   siginificant in that the VRTSvlic package must be first,
   the VRTSvxvm package must be second, and then any
   remaining packages:
   #pkgadd -d . VRTSvlic VRTSvxvm VRTSvmdoc \
   VRTSvmman VRTSob VRTSobgui VRTSvmpro \
   VRTSfspro VRTSvxfs VRTSfsdoc
   

Once the Installation is complete as you see below:

** IMPORTANT NOTICE ***
      This machine must now be rebooted in order to ensure
      sane operation.  Execute
             shutdown -y -i6 -g0
      and wait for the "Console Login:" prompt.
# shutdown -y -i6 -g0

Give the above command as it appears in the console.

Once the system reboots, apply any Veritas volume manager
    patches. At the time of this writing, there are no patches
    for neither volume manager or filesystem. However, future
    patches (and there will be patches ;-) can be obtained from
    http://seer.support.veritas.com.
    Note that the patch installation instructions may require
    that a reboot be performed after the patch is installed

2) How do I initialize disks in Solaris, so that I can Add to VxVM(Veritas Volume Manager) ?

#drvconfig; devlinks; disks

Also,

try the following, :

#devfsadm

#vxdctl initdmp

#vxdctl enable

Make sure you initialize disk , only then will you be able to add to Veritas Volume Manager.

3) How do you add/remove/replace a Disk to Veritas Volume Manager Control ?

There are 13 options available to choose, from the below command, like adding/removing of devices:

#/usr/sbin/vxdiskadm

4) Steps for setting up storage - Veritas Volume Manager ?

1) It is important to create a diskgroup, so that VVM can be
moved to a different hosts.

Disk Groups includes filesystems/disks of the applcations.
Commands (vxdiskadd or vxdg).

#vxdg init diskgroup diskname=device

example:
#vxdg init ABCdg ABCdg01=c0t0d1

2) Creating Volumes with vxassist:

# vxassist -g diskgroup make vol_name size

example:

#vxassist -g ABCdg make ABC01 8g

Note: Understanding the contents of the /etc/default/vxassist file is important, especially when striping disks.

3) Creating a VXFS filesystem:

#mkfs -F vxfs -o bsize=8192,largefiles /dev/vx/rdsk/ABCdg/ABC01

4) Mounting the VXFS file system.

Creating and mounting filesystems go hand in hand. You must be certain that any special flags

set at creation time are reflected in /etc/vfstab, or on the command line if there is no entry in vfstab for your filesystem.

mount -F vxfs -o largefiles /dev/vx/dsk/ABCdg/ABC01 /u03/oradata/ABC

4) How do I view the total number of Disks added to VXVM ?

First Check if Veritas Volume Manager has seen the Disks
that you have attached :

#vxdisk -o alldgs list

if not, try the following, and then repeat the previous step:

#devfsadm

#vxdctl initdmp

#vxdctl enable

This should be able to detect disks into VVM

#vxprint

Disk Group rootdg (default disk group for Veritas Volume Manager).

TY | Name | Assoc | Kstate | Length

dg | rootdg | rootdg | ----------- |

dm | disk01 | c2t1d0s2 | ----------- | 17678493

dm | disk02 | c2t2d0s2 | ----------- | 17678493

dm | disk03 | c2t6d0s2 | ----------- | 17678493

We have 3 VXVM disks named disk01, disk02, disk03,

They are labelled dm which represents VM disk.

The VM disks are a member of "rootdg" which is the default disk group.

The size of the disks can be determined by dividing Length by 2, which is actual KB.

5) What are Disk Groups ?

A collection of VM disks that share common configurtion like objects,

their attributes and connections.

Default disk group is rootdg.

A diskgroup name can be 31 characters long.

Diskgroups allow you to group disks in logical collections.

It can be moved as a unit from one host machine to another.

6) How do I view the List of existing Disk Groups ?

#vxdg list

To View more detail about a particular disk group :

#vxdg list (diskgroupName)

#vxdg list rootdg

7) How do I create a Disk Group ?

#vxdg init diskgroup diskname=devicename

For eg. to create a disk group name mktdg on device c1t0d0s2

#vxdg init mktdg mktdg01=c1t0d0s2

8) How do I remove a disk from the disk Group ?

#vxdg -g [groupname ] rmdisk [diskname]

For step 7 to be removed :

#vxdg -g mktdg rmdisk c1t0d0s2

9) What is a Sub-Disk ?

A VM Disks can be divided into one or more sub-disks.

The default name for VM disk is disk ## (such as disk01)

Default name for sub-disk is disk ## - ##

for eg. disk01-01 is the first sub-disk on the VMdisk named disk01.

10) What is Plex ?

You can organise sub-disks to form a plex by using below methods :

Concatenation

Striping (RAID - 0 )

Mirroring (RAID - 1)

Striping with Parity (RAID - 5)

11) Understaning Physical Disks in Sun o/s ?

c# Specifies the Controller

t# Specifies the Target ID

d# Specifies the Disk

s# Specifies the Partition or slice

For eg. c0t0d0s2 , is the entire hardisk connected to controller number 0 in the system,

with target ID of 0, and Physical Disk number 0.