Kernel upgrade from 701 to 720

[Former Member]

Dear Experts,

We have SAP ECC6.0(ehp4) with cluster environmemnt in production system,having 2 nodes CI & DB and one dialog instance. Tried to upgrade
kernel from 701 to 720,but cluster services couldn't started, we had to revert the changes.BASIS release-> 701 sp8 .Below are needful details:

1. Downloaded SAPEXEDB_300-10007263.SAR and SAPEXE_300-10007264.SAR frommarket place.
2. Made directory to_be_kernel & uncar .SAR files in this.
3. Directory to_be_kernel was placed in /sapmnt/<SID>.

Implementation steps->

shut down the cluster services & stop the dialog instance

For CI

1. Log on as user <sid>adm on unix
2. cd /sapmnt/<SID>
3. ls -l
exe to_be_kernel

4. copy all files & directories of existing exe to to_be_kernel.
5. Rename existing exe to exe_old
mv exe exe_old
6. Rename existing to_be_kernel to exe
mv to_be_kernel exe
7. Log on as user root on unix
execute ./saproot.sh

For DB

1. Log on as user <sid>adm on unix
2. cd /sapmnt/<SID>
3. ls -l
exe to_be_kernel

4. copy all files & directories of existing exe to to_be_kernel.
5. Rename existing exe to exe_old
mv exe exe_old
6. Rename existing to_be_kernel to exe
mv to_be_kernel exe
7. Log on as user root on unix
execute ./saproot.sh

For Dialog instance

Assuming, kernel replicates in dialog instance, when server is up.

Then, we checked in both CI & DB using disp+work -v, it reflected new  kernel version.But cluster services fails to started. Same implementation plan was successfully executed in Development & Quality server (standalone servers).

Profile Parameter->

DIR_CT_RUN-> /usr/sap/<SID>/SYS/exe/run
DIR_EXE_ROOT-> /usr/sap/<SID>/SYS/exe

Please suggest!!!!

[Former Member · Accepted solution]

Hello Sumit,

Please check the note 19466 to perform a kernel update.
19466 - Downloading SAP kernel patches

You can also check the following link for a kernel update in unix:

http://sapbasisnotes.blogspot.in/2007/11/update-sap-kernel-in-unix-based.html

Best Regards,

Sandhya

[Former Member · Accepted solution]

  Hello Sandhya,

Information provided by you is for kernel upgrade for standalone servers. Ours is Cluster services....

[Former Member · Accepted solution]

  Hi All,

  Memory parameters correctly set. Problem solved.

[Former Member]

Hi Sumit;

I have the same issue on one of our systems; could you tell me which parameters you found to be changed by the Kernel Upgrade; I looked through the Profile but there are no obvious changes.

Thanks;

Horatiu

[Former Member]

Hi Horatiu,

1) See this is known issue with kernel 7.20. We are on SUSE linux environment (64 bit). After kernel upgrade our parameter es/implementation changing from map to std value. Both std/map are right for 64 bit linux env. but recommended one is std value

std value->  need to set Memory parameters manually as per note#941735

map value->  Memory management taken care by Zero Administration Memory Management concept of SAP

so decision is yours if you go for std-> set memory parameters manually as per your hardware conf, users base etc....also read sap note#941735

if want to keep map value-> maintain parameter es/implementation = map explicitly in the instance profiles of the system to stay with Zero Administration Memory Management concept of SAP

SAP also acknowledge this as a BUG in 7.20 kernel

2)  As per note#Note 1636252, Please go for 7.20 ext kernel, Before this upgrade OS & Database. Below are excerpts:-

[Former Member]

To answer on your question please describe your problem in detail and attach log files to analyze. For correct kernel upgrade procedure please read Note 1636252 - Installing a 7.20 kernel in SAP Web AS 7.00/7.01/7.10/7.11.

Regards

Roman

[Former Member]

  Dear Roman,

That's fine, I read this SAP NOTE. is this note specific for cluster services Please make me clear, whether there is other procedure in cluster service

Bcoz , in QAS & DEV (standlone servers), we followed simple copy & move process, done successfully-> 

1. Log on as user <sid>adm on unix
2. cd /sapmnt/<SID>
3. ls -l
exe to_be_kernel

4. copy all files & directories of existing exe to to_be_kernel.
5. Rename existing exe to exe_old
mv exe exe_old
6. Rename existing to_be_kernel to exe
mv to_be_kernel exe
7. Log on as user root on unix
execute ./saproot.sh

NOTE mentioned by you, suggessting upgrade kernel in /usr/sap/SID/sys/exe/run
but we have done from /sapmnt/SID

i confused a lot. please help, there are lot queries->

1 whether we proceed with /usr/sap/SID/sys/exe/run  OR /sapmnt/SID, however already done successfully with /sapmnt/SID in QAS & DEV, but NOTE suggessting otherwise

2. apart  from mentioned .SAR files in my query, anything require to download. we downloaded latest patch level .
3. In cluster services, is it require to upgrade both CI & DB
4. we were able to see version upgrade vfrom OS level..

Please guide me , if possible

[Former Member]

Hi Sumit,

I am not sure why you are copying existing kernel files in /sapmnt/SID/exe to /sapmnt/SID/tobekernel..

in step 4...

SO you extracted your new kernel files in to be kernel and there is no need of step 4

moreover ... in UNIX, the SAP file directory concepts works bit different..

whatever suggested in the note is correct... you will have a link from /usr/sap/SID/SYS/exe/run to /sapmnt/SID/exe folder .. so the original files reside in /sampnt/SID/exe and even if you come via /usr/sap/SID/SYS/exe/run also it will bring you to the same location..

Please paste the error logs which you are getting.

Thanks,

Jagadish.

[Former Member]

Please attach log files to analyze your problem. Also provide information about OS and cluster solution used, your cluster configuration.

Regards

Roman

[Former Member]

Hi Sumit,

Have checked teh kernel version on your application instance (DI) ?

We are also running the clustor environment on HP-UX 11i v3 we have done the same activity as Jagadesh mentioned.

Please provide the error message  ?

[Former Member]

Dear All,

We had succesfully upgrade kernel version from 701 to 720, we upgraded kernel in below paths:-

1. /usr/sap/SId/SYS/exe/run

2. /sapmnt/SID/exe

3. /usr/sap/DVEMBGS00

but, post upgradtion, all process went  on hold/PRIV mode, memory consumption increased. SAP became too slow. Upon analysis, we found some  memory parameters value changed.   We had to revert the changes.

Can anybody tell us. What was the cause. We tried same scenario in QAS, there are also same result. I think, this is unknown bug in kernel upgrade

[Former Member]

Hi Sumit,

You upgrade kernel in either /usr/sap/SID/exe/run or /sapmnt/SID/exe.

Why you have upgraded the same in /usr/sap/DVEMBGS00 ?

See the below notes

1629598 - SAP Kernel 720 will replace older kernel versions

Note 1636252 - Installing a 7.20 kernel in SAP Web AS 7.00/7.01/7.10/7.11

Regards

Ganesh Datt Tiwari

[Former Member]

Hi,

If problem still persists please provide the extracts from below mentioned logs:

sapstartsrv.log
sapstart.log
dev_disp

Also please have a look at SAP Note 995116.

Regards,
Sachin

[Former Member]

Hi Ganesh,

1.) It is confirmed, Ugarding to 7.20 kernel  affect Memory management parameters. SAP also acknowledge this as a BUG in 7.20 kernel

Please set below parameter explicitly in instance profile....

es/implementation->map

2)  For Cluster services, Kernel should be upgraded in all below stated File systems->

a)     /usr/sap/SID/exe/run

b)       /sapmnt/SID/exe

c)      /usr/sap//SID/DVEMBGS00/exe

[Former Member]

Hi Sumit,

You should copy new kernel files in existing old exe folder. But here you are replacing new kernel files with old one. Hope you understood my point.

Regards, Premlesh

[Former Member]

Hi Premlesh,

Please check carefully:

  From starting we have below folder under /sapmnt/<SISD>

ls -l

exe   to_be_kernel

What we did is->

Rename  exe to exe_old
and, rename to_be_kernel to exe

Now, ls -l would looks like in /sapmnt/<SID

exe exe_old

I hope, u understand !!!!

[Former Member]

Hi Sumit,

As per my understanding , you are SAP system is running on the Unix enviornment.

So instead of renaming the exe folders .. can you keep the exe folder as it is and take a backup of the old kernel .. and copy the contents of the new kernel to the exe directory.

Please remember in Unix the /sapmnt/SID/exe will have links in the /usr/sap/SID/SYS/exe/run so it should no tbe deleted..

Moreover you need to clean up your instance kernel and run the sapcpe manually as per the 720 sap note...

so that the sapstartsrv services will start with new kernel files.

I did not understand in the DB side why you need to do kernel upgrade again for /sapmnt/SID .. it should be a cluster drive .. am i correct?

Thanks,

Jagadish

[Former Member]

Dear Sumit,

I think there might be issue in copy sequence. You may keep it simple as follow

1. Copy existing exe folder/directory to bkp_exe folder/directory

2. Extract the new kernel directly to exe folder.

Thansk,

Rushikesh

[Former Member]

I have concern on below step:

4. copy all files & directories of existing exe to to_be_kernel.

from this step I understand that you are copying existing kernel filed to new kernel folder.

[Former Member]

  Dear Jagadish,

1. Our system is unix

2. There is nothing wrong in copying , renaming process. Same we have done in QAS & DEV as i mentioned in query

3.  I believe sapcpe process we need to follow, but issue is that, we didnt follow this step also in QAS & DEV,. Is it for cluster services only

4. Bcoz on DB we don't have mount point /sapmnt/<SID>, we go manually->

cd /sapmnt/<SID>
Then update the kernel

Yes, in PRD, we have cluster service