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 |
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 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"> <name>root_disk_fix</name> <version>1.0</version> <parent>none</parent> <diskprop> <filename>root_disk_fix</filename> <vdfile>vdisk.vmdk</vdfile> <owner>root</owner> <max-size>8589934592</max-size> <sectors>16777216</sectors> <description>none</description> </diskprop> </vdisk> |
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.