need ur opinion plz

[meekrob]

Hello,

lately our administration purchased the following and they're planning to setup a 2-nodes cluster with Oracle RAC :

1) 2 integrity rx7640 servers

2) HP-UX 11iv3 BOE and mirrordisk-ux for both

3) ServiceGuard A.11.19

4) SGeRAC

However, i need some clarification on this as they may throw the deployment on us very soon  and it is best to be prepared :(

I dont have any idea about SGeRAC however, i did some research and try to understand what is intended for.

Another concern, don't we need to purchase ECMT (enterprise cluster master toolkit) too to integrate the Oracle package as the 11iv3 BOE does not have it? In your opinion, why did they purchase SG while we have Oracle RAC? and in this case what is the function of SG? who will monitor the Oracle package's health in this case? Is SG only purchased to provide LAN card availability without providing package availability?

Please advice.

Thanks in advance

[Duncan Edmonstone]

Oracle RAC can of course operate on its own without any additional clustering software via CRS, but on HP-UX, it can also operate with Serviceguard Extension for RAC - when operating with SGeRAC, cluster management is done by SGeRAC rather than by CRS - this is generally considered to be a "good thing" as Serviceguards abaility to deal with failures at the hardware/OS level is probably superior to those in CRS. So as you have SGeRAC, I would advise you to use it.

You don't need ECMT - that is only required for non-RAC Oracle databases.

[meekrob]

Many Thanks for your prompt reply and still need to know the following if possible:

in that case and as we only need to use SGeRAC and not ECMT, what would be the monitoring script for the package and in your opinion and logically speaking what would be the package to guard? is it the RAC itself? As i know that ECMT provides monitoring script for the Oracle Database so, in the package control script what would be the value for the SERVICE_CMD parameter in that case?

In addition, do we need to purchase a volume manager license other than LVM?

Please i need your help as im new to high availability concept just to have a clearest view.

Is there some doc or white paper on the config of SG with SGeRAC that can help as i searched the websites and all what ive found was release notes that do not provide tech help. Any suggestion on this?

Regards

[Duncan Edmonstone]

I think you need to find yourself a couple of hours and have a good read of the SGeRAC implementation manual:

http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02815374/c02815374.pdf

There are a number of choices over how you implement volume management (raw, raw over SLVM, raw over CVM, straight ASM, ASM over SLVM, Files on CFS over CVM) if you just have SGeRAC, then your options are just raw, raw over SLVM, straight ASM or ASM over SLVM. There's a chapetr on all this in the manual, make sure you read the one relevant for 11iv3.

But honestly my best advice would be to get someone in who has built a SGeRAC cluster before - there are plenty of gotchas, and the integration can be pretty complex at times - a helping hand may end up costing less in terms of the amount of time you take to do this.

[meekrob]

Once again many thanks for your help and advice.

The problem is that i need to understand the whole concept.

You also mentioned the following: "if you just have SGeRAC, then your options are just raw, raw over SLVM, straight ASM or ASM over SLVM" what do you mean by that and what is the other option than only having SGeRAC?

Are there some detailed HP courses for SGeRAC out there (instructor LED or other?)

Regards

[Duncan Edmonstone]

RAC needs to access disk LUNs from all nodes in the cluster concurrently - - that leads to a number of different storage options which are covered in the SGeRAC manual... if you have just SGeRAC the options are as I described above, the most common used with the latest versions of Oracle being ASM or ASM over SLVM.

The other options are if you have also purchased Serviceguard Storage Management Suite, which would allow you to use the Cluster Volume Manager from Symantec/Veritas, or the full Cluster Filesystem from Veritas/Symantec - as you don't mention that as something you have purchased, I would assume its not an option for you.

I'm not aware of any courses on just SGeRAC, although I believe it is covered in one of the Serviceguard courses:

http://h10076.www1.hp.com/education/datasheets/u8601s.pdf

I don't know if that course is offered in your country though (and I don't know what country you are in).

[meekrob]

Hello, thats right as on the list of purchases there is not Serviceguard Storage Management Suite listed.

Actually im in UAE however, how can i start learning from zero on how to deploy such solution which will be critical for our businesses? I already have some knowledge in ServiceGuard but ive never had the chance to know RAC or SGeRAC before.

So, if you just put yourself in my shoes, from where do you advice me to start just to not getting confused ?

Thanks in advance

[Duncan Edmonstone · Accepted solution]

It's difficult, but I would certainly start by reading the manual and some of the white papers here:

http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?lang=en&cc=us&taskId=101&prodClassId=10008&contentType=SupportManual&docIndexId=64255&prodTypeId=18964&prodSeriesId=4162084#3

But probably better to get in touch with your local HP office and see what services/capability they have available locally:

http://welcome.hp.com/country/emea_middle_east/en/companyinfo/headquarters.html

[meekrob]

Many Thanks for your precious help and time.

Regards

[Travis Harp_1]

I have a set up similar to this and the reason we use RAC and Serviceguard together is that RAC by itself won't mount our Veritas CFS volumes. (Apparently only Oracle owned filesystems are worthy)

Because all SG is doing in our environment is mounting the database CFS filesystems then running the RAC start command I've disabled most SG monitoring as RAC handles it, with both clustering packages monitoring resources we had them step on each other a couple times.

To SG's credit and in this case downfall, it's more easily configured than RAC so we removed monitoring from SG and let RAC handle it.

In our environment SG ends up being a fancy file system mounting script.

If you aren't using a file system outside the ones supported by RAC I would guess that SG isn't needed in the environment.

[meekrob]

Hello,

im new to serviceguard and I still have 1 question in mind and i thought that you can help:

supposing that i need to configure a SG Failover  package using LVM (shared LVM) (on a 2-nodes cluster with cluster lock LUN).

Is there a way to setup this package as dependent of 2 shared VGs with 5 or 6 lvols each (let's say vg02 and vg03) same as we proceeded for the vg01 which constitutes the cluster Lock LUN? (is it possible to create the vg 1st on the 1st node then vgexport/vgimport and configure it within the package config and control file as we did for vg01?)

In this case it is just a standard package ensuring availability of shared filesystems, so, how to also configure SG to monitor this package? What would be the SERVICE_CMD parameter value within the package's control script in that case?

I guess that we can mount file systems as sLVM however we need Veritas so that both nodes can access shared data concurrently isn't it? correct me if im wrong.

Regards