Dennis,
NOMAD Shared Databases can utilize dataspaces. It's implemented by merely
adding a LOOKUP DATASPACE clause to the desired MASTER definitions, then
issuing a SCHEMA CHECK command. No application code need change to take
advantage of the facility.
So it's conceivable a DBA implemented dataspace use at the database level, with
the unmodified application code transparently benefiting from this database
enhancement.
Regards,
Tom Ramsberger
Select Business Solutions
Kris,
NOMAD servers are not listed in QUERY RESOURCES. After thinking about
it some more, I seriously doubt they use dataspaces. Most of the NOMAD
code predates the existence of dataspaces. Bill Holder's explanation is
more likely. The workload on the system is CMS, so I'm sure there's a
fair amount of segment usage. It's not a problem, just curiosity, so I
won't worry too much about it.
Dennis O'Brien
"Elected office holds more perks than Elvis' nightstand." -- Dennis
Miller
-----Original Message-----
From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On
Behalf Of Kris Buelens
Sent: Saturday, May 17, 2008 13:57
To: [email protected]
Subject: Re: [IBMVM] Mystery paging
Maybe Q RESOURCES will reveal the userids of the NOMAD servers, then Q
SPACES USER xxxx will show some dataspaces.
2008/5/17 O'Brien, Dennis L <Dennis.L.O'[EMAIL PROTECTED]>:
> Kris,
> Thanks. That's interesting reading. The system in question does not
> have DB2/VM, and the 3 SFS filepools have no directories eligible for
> dataspaces. Any other ideas? Do NOMAD2 Shared Databases use
> dataspaces? I know this system has NOMAD2 Shared Databases, but as
> we're just getting familiar with it, I don't know their userids. I
> don't think there's anything wrong with the system, it's just
curiosity,
> so it's not worth any great effort.
>
> Dennis O'Brien
>
> "Elected office holds more perks than Elvis' nightstand." -- Dennis
> Miller
>
> -----Original Message-----
> From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED]
On
> Behalf Of Kris Buelens
> Sent: Saturday, May 17, 2008 11:52
> To: [email protected]
> Subject: Re: [IBMVM] Mystery paging
>
> Are dataspaces being used? DB2 and SFS are the the most common
> examples. With dataspaces (mapped to minidisks), the application
> simply reference the storage, CP will page-in what is referenced, and
> that is counted as paging.
>
> CP's Q SPACES and IND SPACE commands can help you.
>
> On VM's web-site, there is a document were I describe this in more
> detail:
> http://www.vm.ibm.com/perf/tips/dim.html
> http://www.vm.ibm.com/perf/tips/vmdspage.html
>
> 2008/5/17 O'Brien, Dennis L <Dennis.L.O'[EMAIL PROTECTED]>:
>>
>> We recently inherited responsibility for a z/VM 5.2 system that had
> been
>> maintained by another group. They had a DR test today, and I logged
> on
>> and looked around. The LPAR is configured with 3G central storage
and
>> no expanded storage. I issued the following commands:
>>
>> q alloc page
>> EXTENT EXTENT TOTAL PAGES HIGH %
>> VOLID RDEV START END PAGES IN USE PAGE USED
>> ------ ---- ---------- ---------- ------ ------ ------ ----
>> VMPG00 8719 1 1000 180000 1 1 1%
>> VMPG01 871A 1 1000 180000 0 0 0%
>> VMPG02 871B 1 1000 180000 0 0 0%
>> VMPG03 871C 1 1000 180000 0 0 0%
>> ------ ------ ----
>> SUMMARY 720000 1 1%
>> USABLE 720000 1 1%
>> Ready;
>> ind
>> AVGPROC-003% 01
>> MDC READS-000112/SEC WRITES-000003/SEC HIT RATIO-093%
>> PAGING-13/SEC STEAL-000%
>> Q0-00003(00000) DORMANT-00141
>> Q1-00000(00000) E1-00000(00000)
>> Q2-00001(00000) EXPAN-001 E2-00000(00000)
>> Q3-00000(00000) EXPAN-001 E3-00000(00000)
>>
>> PROC 0000-003%
>>
>> LIMITED-00000
>> Ready;
>> q xstor
>> Expanded storage is not available within this hardware configuration.
>> Ready(01401);
>>
>> Since there's no expanded storage, where are those 13 pages/second
>> going? Is the system reading the one page that's out on DASD 13
times
> a
>> second? I did another Q ALLOC PAGE after the IND, and there's still
>> only one page out there.
>>
>> Dennis O'Brien
>>
>> "Elected office holds more perks than Elvis' nightstand." -- Dennis
>> Miller
>
>
>
> --
> Kris Buelens,
> IBM Belgium, VM customer support
>
--
Kris Buelens,
IBM Belgium, VM customer support
