Download BEGINNERS GUIDE TO LDOMS

Guidelines and Gotchas
Sun Microsystems, Inc.
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Other Resource Management Techniques and Logical Domains
If you use processor sets within the Solaris OS in a logical domain, attempting
to remove the last virtual CPU of a processor set using Logical Domains Manager
commands may fail. You need to remove the processors from the set first, from
within the Solaris OS environment.
Network Install Onto a Virtual Disk Devices
Currently, exporting virtual disks backed by ZFS volumes and disk slices do
not allow network installation. To use network installation, you must use a virtual
disk that is backed by a complete disk or image file. These can take the form of a
physical spindle in the system, a LUN located on a SAN device or even a file on
UFS or ZFS local to the control or service domain. Additionally, the operating
system can be transferred from an existing Solaris OS installation to the disk slice
or file-based disk service and used to run a logical domain. The scope of this
procedure is beyond this document.
Summary
Again, there are lots of aspects to consider when configuring domains. To
summarize these:
Do’s
4 Allocate sufficient resources to the control domain so the Logical Domains
Manager and its associated processes can run effectively.
4 Provide enough computing resources to the I/O domain to be able to process
the expected loads of I/O traffic generated by guest domains.
4 Allocate virtual devices to guest domains where possible to improve flexibility.
Assign direct devices only where needed.
4 Be mindful of the relationship between the processing threads of a core, and
ensure the virtual CPUs of a core are all assigned to the same domain where
possible.
4 Use a complete disk if you want to perform a network installation of the Solaris
OS.
Don’ts
8 Don’t forget you need to remove processors from processor sets in a guest
domain operating system before being able to dynamically remove virtual
CPUs from those sets.
Beginners Guide to LDoms — July 2007