Frequently Asked Questions: Hitachi LPAR
Here you can find frequently asked questions on SAP on Hitachi LPAR. If you need more informations about Hitachi/HDS SCN and SAP Notes check out to:
- Note 2063057 - SAP HANA VMs on Hitachi LPAR in production
- Note 2025249 - Linux: SAP on Hitachi HVM LPAR virtualization
- SCN DOC-57936 - SAP on Hitachi LPAR
- SCN DOC-57937 - SAP Notes Related to Hitachi / HDS
1. What is Hitachi LPAR(*1)?
Hitachi LPAR is Hitachi's hardware partitioning system provided via firmware that is offered as a feature on the Hitachi server products such as the BladeSymphony or Hitachi Compute Blade. Hitachi LPAR is certified as a feature of a specific hardware system and is therefore listed as a feature on that system. It is not a separate software offering that a customer can purchase and install on other hardware (Hitachi or otherwise). Hitachi LPAR is enabled on Hitachi servers via their Baseboard Management Controller (BMC) prior to booting the operating systems. It is supported by Hitachi like their system BIOS, BMC, service processor and other hardware functions.
For additional information see the Hitachi website:
- For the BladeSymphony: http://www.hitachi.co.jp/virtage/ (Japanese)
- For the Hitachi Compute Blade: http://www.hds.com/products/compute-blade/ (English)
(*1) "Virtage" is a trademark for Hitachi's hardware partitioning system. This trademark is only used in Japan.
2. What is the difference between Hitachi LPAR and other virtualization solutions?
Hitachi LPAR builds virtual environment as each division with high independency called a logical partition (LPAR). Moreover, I/O access from each virtual environment are directly performed like a physical server, without hypervisor interventions substantially. The feature of this hardware transparency gives high reliability and high performance.
3. Even if two or more OSs are used on a single physical server, can we have enough performance out of it?
Since a CPU usage rate on a physical server is not always so high, there are many cases where enough performance can be obtained with the server-integration by virtualization. Moreover, since Hitachi LPAR has the specific hardware assistance, generally, a hypervisor's overhead is small and performance is good enough compared with other virtualization solutions. (Please study to request an estimation for environmental transition, in advance.)
4. Is the hardware transparency the feature that only Hitachi LPAR can offer?
Among the server virtualization solutions currently available for IA servers, only Hitachi LPAR has adopted the virtualization technology of logical partition (LPAR) method. Since almost all resources are not virtualized by this method, each OS can control I/O devices just like physical servers. Thereby, almost all application programs and middleware are able to operate as expected.
5. What happens when a hardware failure occurs on a physical server? Do all LPARs go down?
All the logical servers currently running will stop when the fatal failure occurs. For quick recovery, it is effective to use HA options such as N+1 cold standby function, HA monitor and so on. Also, in case of partial hardware failure, Hitachi LPAR has functions to isolate the failing LPAR and to allow running the remaining LPARs.
6. Can I use the OS standard device drivers for Hitachi LAPR?
Yes, you can use the conventional device drivers made for physical servers.
7. What kind of management software can be used for Hitachi LPAR?
It is recommended to use Hitachi Compute Systems Manager(HCSM).
8. I want to use the physical server blades not only as virtual environment but also sometimes as baremetal environment. Is it possible?
You can easily enable/disable Hitachi LPAR mode on your blades from web based console.