Install SAP NW RHEL5.3 Distributed questions

[Former Member]

Hello,

Thank you in advance for helping a newbie. I am looking to install NW, ECC6, EP, and BI on central system and install MAXdb on another system.

1) Is NFS required since I am not using multiple AS? If it is not required how do I export needed information over to db instance. (just copy directory structure and files?)

Also when I went though install, system only allowed me to install central services first(central install needed db installed first).

So am I correct in thinking I install central services, then db instance, then go back to same machine with central services and install central instance.

Again thank you, I have read a ton of install material but since there are so many setups available no real answers seem to jump out.

Jeff

Edited by: Jeffrey Mitchell on Sep 29, 2009 7:09 PM

[markus_doehr2]

> 1) Is NFS required since I am not using multiple AS? If it is not required how do I export needed information over to db instance. (just copy directory structure and files?)

Never use NFS for database files and especially not for MaxDB. The I/O mechanism used will slow down the system tremendously because of NFS latency.

A SAP application communicates with the database using a database client software, the database server and the application don't need to share any directories, they communicate over the network.

Markus

[Former Member]

Hello,

Brian, I am trying to create a distributed system. The central services and central instances are going to be on one IBM x3550 box called central.install.com and the MaxDB is going on a Dell 2850 in a raid1 + raid 5 configuration. The db logs will go on the raid 1 and the db data will go on the raid 5. I am creating this in a distributed environment so I can have better DB performance and so I can increase my basis skills. That being said I am trying to follow the install guide to complete this task.

Per the installation guide for SAP ERP 6.0 SR3 ABAP+Java on Linux: SAP MaxDB

You can use the SAP transport host or the SAP global host as your central instance host.

You perform the following steps:

1. If you want to share the transport directory trans from another system, you have to mount it from this system. Otherwise we recommend that you share the trans directory that is created during the installation of the central instance (see below).

2. On the SAP global host, you run SAPinst and install the Java central services instance (SCS).

OR

3. On the SAP global host, you run SAPinst and install the ABAP and Java central services instances (ASCS and SCS).

(I choose this one)

4. On the SAP global host, you export the required file systems to the database and central instance host.

(I have installed the central services on the global host - since I do not have the central instance installed yet I do not have my trans directory yet. Maybe this is not needed for db instance? So now I am going to export the central instance file system to the DB instance correct (Per Markus this should not be NFS so I should copy the directory over through the export)or can I just do install from installation disks?) I assume the export is achieved by me running SAPinst while on central services instance and choosing export to database. Then on database server importing the package from central services instance and then running install.

5. On the database host, you mount the exported file systems from the SAP global host and SAP transport host.

6. On the database host, you run SAPinst and install the database instance.

7. On the central instance host, you mount the exported file systems from the SAP global host and SAP transport host.

8. On the central instance host, you run SAPinst and install the central instance.

Since I am on step 4/5/6 I hold off on any other questions.

Thanks again,

Jeff

[brian_walker]

Just use the trans directory which will eventually get created during the central instance install. The database does NOT need this. If you're just installing the system to learn, you don't need a global transport directory shared between other SAP SIDs.

Regarding the DB/NFS comment from Markus, I THINK he meant that the data/log directories for the database itself (usually /sapdb for MaxDB) should not be connected to the DB server via NFS. That would, indeed, result in horrible performance. I think it is ok and expected to mount the /sapmnt/<SID> and /usr/sap/<SID> directories on the db host (exported from the central services/central instance host). The only thing the db host should do with those NFS mounts is to possibly put some db userid/password information in a file somewhere while running sapinst (at least that is the way it works for DB2 z/OS).

Brian

[brian_walker]

If I understand correctly, you want to do a "distributed" install with the database on one host and everything else on another host. SAP just sort of assumes NFS is needed to share directories with distributed and HA installs (and it is for if there is >1 app server or standalone message/enqueue). I believe you can choose the distributed install. First, perform the create global directories step on the app servers. Next, perform the database install on the database server(make sure to pick the custom parameters just in case). There will be a screen where you can uncheck the "SAP profiles available" checkbox. Last, perform the app server install app server.

While I've never done this, it should work. If it does not (there may be some steps in the DB install that put the DB username/password in some files for SAP ), you can always try the distributed install again and temporarily setup NFS on the app server, then disable it later since the DB should not really need access to the SAP directories. You might also be able to copy whatever files the DB install generates that SAP needs over to the app server.

I'd stay away from the HA install unless you actually want HA and standalone message/enqueue as it just adds complication without any benefit if HA is not needed.

Brian

[Former Member]

Hello Brian,

Yes I want to have a separate db instance with everything else on the central instance.

"First, perform the create global directories step on the app servers." - Where do I find this option in SAPinst?

Under SAP ERP 6.0 Support Release 3 I have SAP Systems with databases. Under the MaxDB choice I have Central Services Instance(SCS), Database Instance, and Central Instance.

Under Software Life-Cycle Options I have a System Copy with Source System export and Target system installation.

Under the Source system I can choose Export Preparation, Table Splitting Preparation, Database Instance Export, Central Instance Export.

Under the Target System I can choose Central Services Instance(SCS), Database Instance, and Central Instance.

From the software life-cycle options it would look like I have to export data to the database instance and again to the central instance.

Can anyone give the general pathway here for this install?

Jeff

I would guess from what I have read and my options.

1 install Central Services Instance(SCS) on my central system.

2 next under source system export I would export preparation, then table splitting preparation ?? and the database instance export.

3 install db instance on db server using target system installation from central services instance for database instance.

4 next I would have to set up central instance - I guess on the DB instance I export Central Instance export

5 install central instance on original server from step one using target system install for central Instance.

Does that sound right?

Edited by: Jeffrey Mitchell on Sep 29, 2009 10:14 PM

[brian_walker]

Sorry, my instructions were based on the Netweaver 7.0 EHP1 SR1 sapinst. If you don't have a reason not to, why not start with the latest version of sapinst?

Looking at Netweaver 7.0 SR3, it looks like you'll have to do the steps just like you said:

1. SCS

2. DB

3. "central instance"

Hopefully the db install still gives the option not to use an SAP directory. You still might have to copy some files from the db server over to the app server.

Brian

[Former Member]

Hello all,

Thanks for the help so far Brian. I am back now. I have no old trans directory to pull to Global host. I have installed central services instance on central.install.com. Now I am installing the database instance on sapdb.install.com. I am then going to go back and install central instance on central.install.com. My question is do I:

1 export information from central services to database instance first. Then install database instance.

2 Then export information out of the database instance back to central.install.com for central instance.

Do I need to export data again from central services instance to central instance (going on the same box)?

Then per install guide the Trans directory I am to use is the one set up with central instance.

3 Do I need to then export from central instance data this back out to database instance.

Since central services and central instance are on same box do I have to do anything further with central.install.com, ie. export data out of central instance to central service instance.

I know this sounds confusing but any help is greatly appreciated.

Jeff

[brian_walker]

Hello again.

1. On the central services system, there should now be /sapmnt/<SID> and /usr/sap/<SID> directories. These need to be exported via NFS and mounted in the same place on the DB system before installing the DB instance. As I tried to indicate before, you MIGHT be able to get around that and then just copy whatever the database install puts locally in /sapmnt/<SID> and/or /usr/sap/<SID>. Obviously the easier thing to do is to just use NFS.

2. Not sure what you're trying do here. There should only be 1 set of shares from the central services system.

3. Same as #2

As for the trans directory, it is not needed for the DB instance, only for the app server(s) (though there is no harm in it being mounted on the DB server as well). Depending on what you're trying to accomplish, just having trans local on the app server at /usr/sap/trans is fine. If you wanted 1 central transport directory for all systems in a landscape, you might have a transport host (say trans.install.com) which exports the trans directory and then mount it via NFS on all app servers to /usr/sap/trans. That's totally up to your requirements.

Brian