Export Performance R3SZCHK

[CLOEFFLER]

Hello Everyone,

We are experiencing a very bad performance on IBM System  I during a database export (hetereogeneous systemcopy) of a SAP ERP EHP7 system.

Using the latest kernel (742 and SWPM (17) we started the export, but phase R3SZCHK does not come to an end. After 18 hours of running that phase without any data, we stopped SWPM and restarted it. And again: it did not succeed. This time we stopped it already after 12 hours.

On other System I systems we had this phase at about 1 to 3 hours, but have never seen it at more than 10 hours.

We can see that CPU (4) is very busy (100 % CPU) and that disks are working quite well, but cannot figure out what's going wrong here. As well we could not find any SAP Notes pointing to a situation like this on System I.

Any hint how to solve this situation? Thanks in advance for any kind of hint and help.

Kind Regards,

Carsten Loeffler

[volker_gldenpfennig · Accepted solution]

Hi Carsten,

in my eyes, R3Szchk runs single-threaded and with 1 process only. If this is still true, you cannot exhaust 4 CPUs with this ...

So, my first question would be: Do you really have 4 CPUs or perhaps 0,5 CPUs only ...

but: anyway: It does not seem to be fast ...

I woudl suggest to have a look into the OpsNav plancache and check the bad SQLs there ... I would suspect a wrong optimizer decision for this "one statement", that will over and over be called in r3szchck ...Otherwise, you could start the good old DB-Monitor against the r3szchk, while it is running. I would guess, that you will find the root cause there ...

Is OS and PTFs "a bit proper" ? Or do you try to export on a VERY old system ?

Based on EHP7, I would guess, you do have a pretty recent setup there ...

Regards,

Volker Gueldenpfennig, consolut international ag

[CLOEFFLER · Accepted solution]

Hi Volker,

as to our conversion, we re-run the export using the R3SZCHK option "use database-specific implementation (Parameter -s DB)".

This time R3SZCHK finished successfully after 55 minutes. The export afterwards finished successfully as well.

Thank you for valueable assistance!

Kind Regards,

Carsten

[CLOEFFLER]

Hi Volker,

thanks a lot for taking care... 😉

Yes, the system is a pretty new setup running von V7R1. But

I do not know which PTF it uses.

With newer SWPM we were able to run R3SZCHK in parallel.

In the first try we ran it with 6 job in parallel, in the second try

with 5 jobs.

We've seen that CPU was running at 98 % all over the time

of the R3SZCHK.

We cancelled the job right now. Maybe I will get a "third try"

and then go for your suggestion.

By the way: the system is experiencing an overall bad

performance. It is running 4 SAP systems (temporary). That's

why we tried to do a move to Windows / MSSQL.

Kind Regards,

Carsten Loeffler

cormeta ag