Micropartiontiong 2

[kHz]

There are currently seven individual servers that have 10%-20% max CPU utilization on H50’s that are all 332MHz. The breakdown of processors are for the individual servers:

4 servers – 1 CPU (max cpu utilization 20%) ; 512MB memory
2 servers – 2 CPUs (max cpu utilization 20%) ; 1GB & 2 GB memory
1 server – 4 CPUs (max cpu utilization 30%) ; 2 GB memory

The LPARs would be divided among 2 p520s with one server having 3 LPARs and the other p520 running 4 LPARs. Would the p520 have enough capacity to handle the workload above? Disk and network I/O is light. A VIO server is a possibility.

Or would 2 p550’s be better for workload capacity?

 

[metzlej]

If you opt for the 2.1Ghz processor version of the 520 then you should be fine. What helps with sizing servers is the Rperf value - in this case IBM doesn't supply the Rperf value for the H50's and the closest one is the H80.

An example:

H80: 1 processor - Rperf=.93
H80: 2 processor - Rperf=2.02
H80: 4 processor - Rperf=3.55

Total 1 processor machines (4 x 1 processor) Rperf=3.72
Total 2 processor machines (2 x 2 processor) Rperf=4.04
Total 4 processor machines (1 x 4 processor) Rperf=3.55
Total Rperf needed = 11.31

P520 - 2 x 2.1Ghz - Rperf=9.59
P520 x 2 machines - Total Rperf=19.18

I would recommend 2 x VIO servers with .3 processors each and 512MB ram for each P520 machine.

Hope this helps.

Jarrett

 

[mag007]

Here are some 'relative performance'/rPerf reports:

http://www-03.ibm.com/systems/p/hardware/system_perf.html

HTH

 

[kHz]

Thanks for the previous helpful information.

These servers have to have a failover capability because of their use. What if I use a p550 with a VIO server and 7 partitions and then had a failover consisting of 1 p520 and 1 VIO server with 4 partitions and another p520 with a VIO server and 3 partitions?

That would handle failover at the primary site, then have a p550 with 1 VIO server and 7 partitions at the DR site.

Does this sound like an acceptable solution? How does a VIO server failover if the primary site server went down, or the primary VIO server went down?

Thanks.

 

[metzlej]

If you use a 4-way P550 then it should have enough processing power to do what you are asking. However, when using VIO servers (LPAR) it is best to have a minimum of at least two per physical machine. One of the main reasons is that it provides your virtual disks for each LPAR. In the case of the P520 or P550 I believe they have 8 disk bays in the main cabinet. With your server design be sure that IBM includes a SCSI controller to where you have a split bus so that 4 disks go to one VIO server and the other 4 disks to go to the other. This way you can mirror your LPAR Operating System disks from one VIO server to another which provides redundancy.

This just addresses redundancy for each physical server and not the DR questions that you mentioned.

 

[kHz]

Another question. Does the NIM server have to be on an LPAR or can I use my existing standalone NIM server?

 

[mag007]

You can use your standalone NIM.

 

[p5wizard]

You can use whatever NIM server you have, provided it serves the AIX level you need to install on the p5 LPARs.

A gigabit ethernet between the NIM server and the LPARs (possibly via VIOS) is recommended.



HTH,

p5wizard

 

[kHz]

Talking to a VAR this afternoon he mentioned it might be less complex to add 3 expansion cabinets and use HBAs and Ethernet adapters than to use a VIO server.

Would you agree with this? What is the complexity of setting up and managing a VIO server? I have done LPARs before but have never done VIOS and he said it might take some time to become comfortable enough with it, of which time is not what I have a lot of. 6 weeks probably.

What senario(s) can you think of that would hinder using a p550 with 7 LPARs and 2 VIO servers or expansion cabinets and have an identical setup for failover. I need to make sure everything is redundant because the server has to be at five 9s. Or what I might need to increase availability.

 

[metzlej]

There is some validity to the issue of the VAR recommending more physical hardware instead of the Virtualization for complexity issues. VIO can get complicated if you are new to it but it will save you thousands of dollars from not having to purchase the extra hardware.

If you are in a time crunch with having these installed then it might be better to purchase the extra hardware. However, if you have someone that is fluent in the installation and configuration of it or can deal with the time constraints for the learning curve then you should really consider virtualization as an option. Once virtualization is configured, its really easy to an another server in the future (as long as you have CPU and memory resources available). As long as you have redundant VIO servers in each physical server and you have redundant ethernet connections to each vio server then you should be just fine. As far as DR purposes you should have a NIM server/lpar in each physical location.

Hope this helps.