HP Integrity Virtual Machines Installation, Configuration, and Administration

7.2.2.3.2 Virtual LvDisks
A Virtual LvDisk is an emulated SCSI disk whose virtual media is provided by a raw VM Host
logical volume. To specify a VM Host logical volume, use a character device file. The character
device file is owned by either LVM or VxVM.
Virtual LvDisks cannot be shared simultaneously across active virtual machines. Only one active
virtual machine at time can be given a particular Virtual LvDisk resource. Virtual LvDisk resources
can be changed dynamically between active virtual machines (see Section 7.3: “Using Integrity
VM Storage” (page 92)).
Logical volumes can be created using the sam utility or the Veritas Enterprise Administrator.
Alternatively, logical volumes can be created using the commands available with the volume
manager. All logical volumes are created on whole disks. The sizes of the logical volumes come
from the space available from their respective volume group types; that logical volume size can
be increased without loss of data in the volume. The character devices for the logical volumes
are created by their respective volume managers at the time the logical volume is created. Also
to avoid file system corruptions for the VM Host and guest , use only raw logical volumes that
contain no VM Host file systems and are not currently mounted on the VM Host.
To prevent data corruptions, keep an account of logical volumes for Virtual LvDisks. To help
with the accounting, use all logical volumes within a given volume group for a single virtual
machine. When logical volumes are configured this way, you only have to keep track of the
volume groups to prevent media conflicts. See Section 7.2.1.4: “VM Storage Management”
(page 78) for information about tracking virtual media allocation.
If you are using LVM, the Virtual LvDisk resource statement takes the following form:
disk:scsi::lv:/dev/vg_name/rlvol_name
Where /dev/vg_name/rlvol_name is an LVM character device file for rlvol_name on
vg_name. To display the LVM character device file name, enter the following command:
# vgdisplay -v
VG Name /dev/lvrackA
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 4
Open LV 4
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 8683
VGDA 2
PE Size (Mbytes) 4
Total PE 8681
Alloc PE 8192
Free PE 489
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0
--- Logical volumes ---
LV Name /dev/lvrackA/disk1
LV Status available/syncd
LV Size (Mbytes) 8192
Current LE 2048
Allocated PE 2048
Used PV 1
LV Name /dev/lvrackA/disk2
LV Status available/syncd
LV Size (Mbytes) 8192
Current LE 2048
84 Creating Virtual Storage Devices