System Sizing Guidelines for Integrity Virtual Machines Deployment -- Hardware Consolidation with Integrity Virtual Machines

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For most Integrity systems, the memory required for I/O adapters is negligible. One exception is
the HP Integrity BL8x0c i2 Server Blade system – based on the Intel Itanium processor 9300 series.
The 10GbE (10GigE) network ports on BL8x0c i2 server blades require an additional 500MB of
memory per 10GbE network port when they are configured for Flex10 or jumbo frames. If
these ports have both Flex10 and jumbo frames enabled, then the additional memory requirement
is 1GB per 10GbE network port. Refer to latest memory subsystem documentation for
changes to these requirements.
For example, consider a BL860c i2 server blade with 64GB of memory with the default number of
10GbE network ports (4). If those ports are configured for both Flex10 and jumbo frames, then the
VM Host memory requirement for that system is:
1.2GB + 8.5% × (64GB) + (4 adapters * 1GB/port) = 1.2GB + 5.44GB + 4GB = 10.64GB
Memory Requirements for each Virtual Machine
When defining a virtual machine to host a given workload, allocate the amount of memory as
recommended for a physical Integrity server hosting that same workload. Defining a virtual
machine with less memory than is recommended for the workload will lead to performance
problems – just as it would on a physical system.
The physical memory required for VMs is the sum of sufficient memory for its operating system and
workload plus an additional 8.0 to 8.3% of the VM‟s memory (as specified in its configuration) for
VM Host data structures.
Best Practice
To simplify sizing exercises, HP recommends you always allow for
the maximum memory overhead for VM memory: 8.3%.
Calculating the Virtual Machine Capacity of an Existing Server
This section illustrates the use of the requirements discussed above to size an Integrity system for use
as a VM Host.
VM Host Memory and Storage Sizing Example
On a physical Integrity server with 16 GB of physical memory and assuming a swap space size of
4 GB, calculate the disk storage requirements as follows:
(Host OE installation) + (swap space)
 20 GB + 4 GB = 24 GB Mass Storage
Calculate the memory required for the VM Host (independent of VM requirements) as follows:
1.2 GB + (8.5% of physical memory)
= 1.2 GB + 8.5%  16 GB  2.56 GB Physical Memory
As a result, the total amount of memory available for use by virtual machines on this system is:
(16 GB – 2.56 GB) = 13.44 GB