DB2 LUW on RHEL KVM

Vijay Shankar Arunachalam

DB2 LUW on RHEL KVM

I installed DB2 luW 11.5 on RHEL KVM and facing issues with operations. The install itself is going through without any issues, and I am able to create a DB2 Instance. First explicit connection to the instance with password locks up the server / instance with db2sysc hitting 100% CPU. There is nothing on the diaglog (with diaglevel 4) or any other linux logs. Below are the sequence of steps.

a) Installed all necessary pre-requisites - basically just 32 bit pam and libstdc++ libraries
b) Installed db2 data server - no purescale
c) create ese db2inst1 instance (no database yet)
d) "Db2 attach to db2inst1" - works perfectly.
e) "db2 attach to db2inst1 user db2inst1 using xxxxxx" - hangs indefinitely

Local users, no fancy ldap, sssd etc. No SSL. My Host OS is RHEL 8.2 with all the latest updates. I tried the below guests with the same results.

a) Rhel 8.2 (I realized that this is not in the supported OS list for DB2 Luw 11.5 )
b) RHEL 7.5
c) centOS 7.5

My hunch is, there is something on the new host kernel (4.18) that is making db2 slip. While i understand i am trying something that may not be fully supported yet (rhel 8), I am looking for any workarounds to make this work. I was hoping to keep the guest at a supported version, but it is not working, as such.

I am trying hard not to degrade my RHEL to a 7.x version with a 3.10 kernel as I was hoping DB2 will bring support to rhel 8 sometime very soon. 

Thank You
Vijay

Ian Bjorhovde

DB2 LUW on RHEL KVM
(in response to Vijay Shankar Arunachalam)
You'll be much more likely to get an answer to this question if you ask on
the Db2 EAP forum.

https://community.ibm.com/community/user/hybriddatamanagement/communities/community-home?CommunityKey=348b0eb4-5e06-4fde-9fe8-97f56a924c17



On Tue, Jun 23, 2020 at 4:05 AM Vijay Shankar Arunachalam <
[login to unmask email]> wrote:

> I installed DB2 luW 11.5 on RHEL KVM and facing issues with operations.
> The install itself is going through without any issues, and I am able to
> create a DB2 Instance. First explicit connection to the instance with
> password locks up the server / instance with db2sysc hitting 100% CPU.
> There is nothing on the diaglog (with diaglevel 4) or any other linux logs.
> Below are the sequence of steps.
>
> a) Installed all necessary pre-requisites - basically just 32 bit pam and
> libstdc++ libraries
> b) Installed db2 data server - no purescale
> c) create ese db2inst1 instance (no database yet)
> d) "Db2 attach to db2inst1" - works perfectly.
> e) "db2 attach to db2inst1 user db2inst1 using xxxxxx" - hangs indefinitely
>
> Local users, no fancy ldap, sssd etc. No SSL. My Host OS is RHEL 8.2 with
> all the latest updates. I tried the below guests with the same results.
>
> a) Rhel 8.2 (I realized that this is not in the supported OS list for DB2
> Luw 11.5 )
> b) RHEL 7.5
> c) centOS 7.5
>
> My hunch is, there is something on the new host kernel (4.18) that is
> making db2 slip. While i understand i am trying something that may not be
> fully supported yet (rhel 8), I am looking for any workarounds to make this
> work. I was hoping to keep the guest at a supported version, but it is not
> working, as such.
>
> I am trying hard not to degrade my RHEL to a 7.x version with a 3.10
> kernel as I was hoping DB2 will bring support to rhel 8 sometime very soon.
>
> Thank You
> Vijay
>
> -----End Original Message-----
>

Vijay Shankar Arunachalam

RE: DB2 LUW on RHEL KVM
(in response to Ian Bjorhovde)

Thanks for the pointer. I just posted at the EAP forum as well

regards

Vijay

Roland Schock

RE: DB2 LUW on RHEL KVM
(in response to Vijay Shankar Arunachalam)

Hi Vijay,

can you reproduce the issue with a 3.10 kernel?  ;-)

If the attach works but an attach with login credentials, it could be the authentication part, which goes wrong. Then you could have a look into /var/log/messages.

Can you create a database sample with db2sampl? Aka test, if engine is running properly.

Are there any messages in the db2diag.log? If not, you could try a 'db2pd -stack all' or 'db2fodc -hang basic' to get an idea, where at all Db2 might hang.

I could imagine the authentication or memory allocation or log file allocation could be slightly different.

 

In the end, I'm pretty sure, IBM knows, why they don't yet support this kernel.

 

Cheers

Roland

Vijay Shankar Arunachalam

RE: DB2 LUW on RHEL KVM
(in response to Roland Schock)

Roland

Thanks for your pointers.

This issue occurs only on KVM guest on a 8.2 . I have working copies on centos 7.5, SLES 12 that are running fine without any issues.

I tried to compare the diaglog entries between the KVM and regular installation on a centos and it does not seem to indicated that anything is off with authentication - there is nothing like, "waiting for auth", but i guess that could be the case too. 

I tried after creating a database - did not help. It was db2bp turn to hit 100% CPU and hang out there. I somehow thought the create database took a lit bit more time (read forever). But that could just be my impatience.

I will dig some more with the db2pd and db2fodc and see what comes out. I have also posted the question at the DB2 EAP forum, let me see if I get any kind of response.

There is a planned GA for 11.5.4 on June 30th and I read somewhere in that support for rhel 8 is expected with 11.5.4.4. So it might be sometime before we FP4 on the June release.

Regards

Vijay