System Administration Guide: Virtualization Using the Solaris Operating System


Creating a Default vmdk:sparse File

A directory of the vdisk name is created and populated with two files. vdisk.vmdk is the file with the disk data. vdisk.xml is the file containing information about the disk, such as creation time, type:option of disk, and snapshot information. Note that vdisk.vmdk has a suffix of the vdisk type.

# vdiskadm create -s 8g root_disk
# ls -l root_disk
total 82
-rw-------   1 root     root     1114112 May  8 16:15 vdisk.vmdk
-rw-r--r--   1 root     root         584 May  8 16:15 vdisk.xml

Creating a vdisk File of Type vhd

The suffix specified is now vhd. Since the option isn't specified with a type, the option has the default of sparse. Note that the disk file, vdisk_vhd, isn't fully populated to 8G.

# vdiskadm create -s 8g -t vhd root_disk_vhd
# ls -l root_disk_vhd
total 44
-rw-------   1 root     root       21504 May  8 16:15 vdisk.vhd
-rw-r--r--   1 root     root         590 May  8 16:15 vdisk.xml

Creating a vmdk:fixed File

Creating a vmdk type vdisk with option fixed takes a minute or more to create since it is creating and initializing 8G of data. The creation time is dependent upon the size of the vdisk.

# vdiskadm create -s 8g -t vmdk:fixed root_disk_fix
# ls -l root_disk_fix
total 16785428
-rw-------   1 root     root     8589934592 May  8 16:18 vdisk-flat.vmdk
-rw-------   1 root     root         638 May  8 16:18 vdisk.vmdk
-rw-r--r--   1 root     root         593 May  8 16:18 vdisk.xml

The contents of the xml file for root_disk_fix are:

# cat root_disk_fix/vdisk.xml
<?xml version="1.0"?>
<!DOCTYPE vdisk PUBLIC "-//Sun Microsystems Inc//DTD xVM Management All//EN" "file:///usr/share/lib/xml/dtd/vdisk.dtd">
<vdisk readonly="false" removable="false" cdrom="false" creation-time-epoch="1241821124" vtype="vmdk" sparse="false" rwcnt="0" rocnt="0">

This same information can be retrieved from the vdiskadm command by using the subcommand prop-get:

# vdiskadm prop-get -p all root_disk_fix
readonly: false
removable: false
cdrom: false
creation-time-epoch: 1241821124
vtype: vmdk
sparse: false
rwcnt: 0
rocnt: 0
name: root_disk_fix
version: 1.0
parent: none
filename: root_disk_fix
vdfile: vdisk.vmdk
owner: root
max-size: 8589934592
sectors: 16777216
description: none
effective-size: 8589935230
creation-time: Fri May  8 16:18:44 2009
modification-time: Fri May  8 16:18:44 2009
modification-time-epoch: 1241821124

The modification times and effective size are all derived “on the fly,” and are not stored in the xml file. The creation and modification times are shown both in epoch format and in human readable format, for use by both software applications (such as Sun Ops Center) and system administrators.

The rwcnt and rocnt fields shown in the xml file are the reader/writer locks on the vdisk. There can be only one writer at a time, but multiple readers can be using the vdisk. These fields are used to set or reset the reader/writer lock associated with the virtual disk. These fields should not be set or reset by hand; they can only be modified by using vdiskadm ref-inc [-r] vdame or vdiskadm ref-dec vdname. These fields are used by blktap for shared or exclusive use of the virtual disk.