Managing Virtual Disks

This section describes adding a virtual disk to a guest domain, changing virtual disk and timeout options, and removing a virtual disk from a guest domain. See Virtual Disk Back End Options for a description of virtual disk options. See Virtual Disk Timeout for a description of the virtual disk timeout.

How to Add a Virtual Disk

1. Export the virtual disk back end from a service domain.

   # ldm add-vdsdev [-fq] [options={ro,slice,excl}] [mpgroup=mpgroup] \
   backend volume-name@service-name

2. Assign the back end to a guest domain.

   # ldm add-vdisk [timeout=seconds] [id=disk-id] disk-name volume-name@service-name ldom

   You can specify an ID of a new virtual disk device by setting the id property. By default, ID values are automatically generated, so set this property if you need to match an existing device name in the OS. See Virtual Disk Identifier and Device Name.

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   Note - A back end is actually exported from the service domain and assigned to the guest domain when the guest domain (ldom) is bound.

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How to Export a Virtual Disk Back End Multiple Times

A virtual disk back end can be exported multiple times either through the same or different virtual disk servers. Each exported instance of the virtual disk back end can then be assigned to either the same or different guest domains.

When a virtual disk back end is exported multiple times, it should not be exported with the exclusive (excl) option. Specifying the excl option will only allow exporting the back end once. The back end can be safely exported multiple times as a read-only device with the ro option.

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Caution - When a virtual disk back end is exported multiple times, applications running on guest domains and using that virtual disk are responsible for coordinating and synchronizing concurrent write access to ensure data coherency.

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The following example describes how to add the same virtual disk to two different guest domains through the same virtual disk service.

1. Export the virtual disk back end two times from a service domain by using the following commands.

   # ldm add-vdsdev [options={ro,slice}] backend volume1@service-name
   # ldm add-vdsdev -f [options={ro,slice}] backend volume2@service-name

   Note that the second ldm add-vdsdev command uses the -f option to force the second export of the back end. Use this option when using the same back-end path for both commands and when the virtual disk servers are located on the same service domain.

2. Assign the exported back end to each guest domain by using the following commands.

   The disk-name can be different for ldom1 and ldom2.

   # ldm add-vdisk [timeout=seconds] disk-name volume1@service-name ldom1
   # ldm add-vdisk [timeout=seconds] disk-name volume2@service-name ldom2

How to Change Virtual Disk Options

For more information about virtual disk options, see Virtual Disk Back End Options.

• After a back end is exported from the service domain, you can change the virtual disk options by using the following command.

  # ldm set-vdsdev options=[{ro,slice,excl}] volume-name@service-name

How to Change the Timeout Option

For more information about virtual disk options, see Virtual Disk Back End Options.

• After a virtual disk is assigned to a guest domain, you can change the timeout of the virtual disk by using the following command.

  # ldm set-vdisk timeout=seconds disk-name ldom

How to Remove a Virtual Disk

1. Remove a virtual disk from a guest domain by using the following command.

   # ldm rm-vdisk disk-name ldom

2. Stop exporting the corresponding back end from the service domain by using the following command.

   # ldm rm-vdsdev volume-name@service-name