The HMC was introduced for Logical Partition support on the pSeries with the introduction of Power 4 Technology. IBM has continued the process of consolidating server hardware and the Power 5 Technology. The eServer i5 can now run i5/OS and AIX natively on the Power 5 server, as well as Linux. The HMC provides a single-control point for managing hardware and Capacity Upgrade on Demand across multiple operating systems, and eliminates the need for a 'Primary Partition' on the iSeries. What will this mean from an implementation and systems Management perspective? Recently Allyn Walsh, IBM Partner World for Developers (PWD) Technical Support, joined Search400.com for a webcast on Introduction to i5 eServer Hardware Management Console (HMC). A few people had questions for Allyn following the broadcast; below are their responses.
Click here to download Allyn's slides
Can you go to a restricted state on one partition but not the others while using the HMC as console for all partitions?
Allyn Walsh: Yes, each partition is independent and each i5/OS partition can be brought to restricted state using the HMC console interface without any impact on the other partitions.
Can the HMC save/restore LPAR configurations? Can the HMC completely replace the multiple ECS connections for individual LPAR's?
Allyn Walsh: Yes, by 'saving the critical configuration data' on the HMC (please note this must be done using DVD-RAM media) the configuration data can be restored on the same or on another HMC. There are considerations if restoring this LPAR configuration and attempting to update a different managed server. The LPAR information is tied to model/type/serial number of the managed server for which it was created. HMC is not designed to replace ECS. i5/OS PTF maintenance is unchanged by the presence or absence of an HMC. PTF's will still need to be applied to each i5/OS partition through normal operating system procedures. The HMC can function as the Service Focal Point for problem reporting but can not be used to order i5/OS PTF's.
Allyn mentioned dual service processors. When will they be available and will current Power5 system accommodate dual service processors?
Allyn Walsh: I'm sorry, as of today, dual Service Processors (SP's), although 'previewed as a statement of direction' have not yet been formally announced and therefore configuration and availability information is IBM confidential at this time.
You mentioned that the HMC uses it's own DHCP server. Will the DHCP be configurable to only allow a certain amount of connections and from only certain MAC address'? Also, how will this conflict with other DHCP servers in an open network?
Allyn Walsh: The DHCP server can be configure to administer a full class B range of addresses. There is no restriction nor is there the ability to restrict it's services to specific MAC addresses It is recommended that the HMC's DHCP service be restricted to a private network to avoid conflicts with other DHCP servers in an open network.
How is a redundant HMC attached?
Allyn Walsh: Using a switch between the Service Processor (SP) you can connect one or two HMCs to a single port on the SP. Or, since the SP comes with two Ethernet ports, this would allow a second HMC to attach to the second port on the SP. When IBM introduces redundant SP support, another option would be to attach one HMC to the first SP and a second HMC to the second SP.
Just to clarify: if I do a PWRDWNSYS without a restart from an LPAR, is the HMC required to restart the partition?
Allyn Walsh: This is a good question. YES, you would need an HMC to perform the power-on to the partition.
Could you explain a little bit more about the desired memory and processor?
Allyn Walsh: The previous iSeries system there is only the minimum and maximum value. The partition will be configured with a minimum, maximum and desired value for both memory and processor allocation. Using the DLPAR (dynamic LPAR) capability you can add or remove memory or processor allocations as long as you remain with in this range. So this is very similar to prior versions of LPAR support on the iSeries. The 'desired' value is what the partition will attempt to allocate at activation, if it is available. For example, if you specified a processor range of MIN= .1, MAX=1.0 and DESIRED=.5 and at the time that the partition is first activated there was only .2 processor available, the partition would still activate and would allocate the available processor of .2 This is possible because it is equal to or greater than the minimum allocation allowed.
I 'm using the ETH0 port from the HMC to attach the FSP by the direct attachment cable, how the ETH1 port will be useful?
Allyn Walsh: Where ETH1 port can be most useful when you configure this port to be on an open network. Once on an open network, you could use the WebSM client to connect to the HMC from any workstation that can reach the IP address assigned to ETH1 port. This would also allow you to use a TN5250 client to connect to the HMC ETH1 port and then connect to the i5/OS console function, assuming the HMC console session is active and is configured to allow sharing. Another advantage of configuring the ETH1 port to be on an open network would be if this also allowed access to the internet. The HMC fix maintenance would be able to use this connection to download HMC updates and server firmware updates. It would also be usable for 'call home' functions when configured as the service focal point.
Is it possible to perform a entire system backup using the Web SM?
Allyn Walsh: Let me clarify that there is no such thing as an 'entire system backup' if you are referring to a LPAR system. If you mean a full system backup of an i5/OS partition, then the answer is still no, this is not done through WebSM. However, if you have the HMC acting as the system console for an i5/OS partition, you can connect to the HMC using TN5250 and connect to the console session for that partition if it is configured to allow sharing. Since the TN5250 session is 'sharing' the HMC console session, you can do a full system save of that partition just as you would from a traditional green screen console.
There was a mention about education. What kind of education is available on HMC. There were no details about that issue in the presentation.
Allyn Walsh: The IBM Information Center is one excellent source of information.
1. Go to http://www.ibm.com/servers/resourcelink.
2. On the Home page select "Register for a user ID and password".
3. On the Register for Access page, select the type of user ID requested.
4. On the self-registration page, fill in your e-mail address and a preferred ID, then click Submit.