Start MaXDB hit error due to insufficent memory

[Former Member]

Hi,

When trying to start MaxDB instance, I hit this error:

"Check knldiag! Kernel died before reaching ADMIN state..."

From the MaxDB diagnosis doc below, I know it is due to insufficient resource issue.

http://maxdb.sap.com/training/internals_7.6/diagnose_EN_76.pdf

Once I set the user's limits in the unix os to unlimited, I can solve the problem. The MaxDB instance can startup.

However, my question here is: Are there any officially recommended ulimit values I shall set from SAP? Is there any doc for this?

For example, in the NW04s SR3 installation guide, there is one section that has mentioned the proper values for ulimit.

As I am not the owner of the Unix Server, if I set everything to unlimited, I will be questioned unless there is a SAP doc to support...So far I have not found any document from SAP yet.

Please help.

Lars, any advice? 😃

Regards,

Li Bin

Edited by: Li Bin on Jan 7, 2009 4:21 AM

Edited by: Li Bin on Jan 7, 2009 4:28 AM

[Former Member]

Found it in SAP Note 628131. Thanks!

[lbreddemann]

Hi Li,

sorry, you were too quick this time!

Very good learning curve

best regards,

Lars

[Former Member]

How in the world do i view this note? We use MaxDB at our company, but do not use SAP. I found a link to the note, but there is a prompt for a username and password. My SAP community credentials do not allow me in there.

I have this exact problem where i don't know how to tune the number of user tasks based on the ram of my machine (or other factors.)

Any help is appreciated!

[lbreddemann]

>

> How in the world do i view this note? We use MaxDB at our company, but do not use SAP. I found a link to the note, but there is a prompt for a username and password. My SAP community credentials do not allow me in there.

That's correct.

SAP support notes are available to SAP customers, partners and employees only.

> I have this exact problem where i don't know how to tune the number of user tasks based on the ram of my machine (or other factors.)

For the ULIMIT issue: just set every ulimit to unlimited for the os-user that runs the MaxDB kernel on your machine.

Concerning the other questions, please check the documentation and the MaxDB WIKI pages here in SDN.

And, btw, you don't setup the number of user tasks based on the available ram.

Why would you?

The number of user tasks simple depends on how many connected sessions should be allowed at any given time.

Say, you know your application usually needs 20 connections as maximum.

Then you should set MAXUSERTASKS to at least 20 and maybe add some possible spare connections to it.

So you may set it to 30 and you should be fine.

regards,

Lars