Are you saying the MDC READS - 142/SEC could be driving the page space used
to 55%? The paging rate itself is 1/SEC... We added 2 paging volumes to
ensure the system does not run out of paging space.
Our production system is a guest system under z/VM 5.1. I don't know if
this would matter in the explanation as to why the system had a 55% paging
space utilization...
ind
AVGPROC-024% 01
MDC READS-000119/SEC WRITES-000002/SEC HIT RATIO-089%
STORAGE-047% PAGING-0001/SEC STEAL-000%
Q0-00001(00000) DORMANT-00120
Q1-00000(00000) E1-00000(00000)
Q2-00000(00000) EXPAN-001 E2-00000(00000)
Q3-00001(00000) EXPAN-001 E3-00000(00000)
PROC 0000-024%
LIMITED-00000
Ready; T=0.01/0.01 09:14:53
q alloc page
EXTENT EXTENT TOTAL PAGES HIGH %
VOLID RDEV START END PAGES IN USE PAGE USED
------ ---- ---------- ---------- ------ ------ ------ ----
510PAG F005 1 3338 600840 333053 443499 55%
PAG002 F008 1 3337 600660 0 0 0%
PAG003 F00A 1 3337 600660 0 0 0%
------ ------ ----
SUMMARY 1760K 333053 18%
USABLE 1760K 333053 18%
Ready; T=0.01/0.01 09:15:12
Thank you.
Cecelia Dusha
-----Original Message-----
From: Jim Bohnsack [mailto:[EMAIL PROTECTED]
Sent: Monday, September 11, 2006 9:01 AM
To: [email protected]
Subject: Re: z/VM 5.1 Paging
Paging rate and page occupancy are not directly related. Do you have an
earlier number for page occupancy? 55% utilization may just be what is
required in a normal, steady state.
Jim
At 07:57 AM 9/11/2006, you wrote:
>Our production system was migrated from z/VM 3.1 to z/VM 5.1 over the
>weekend.
>
>The paging rate was high this morning on the production system as the
>VM:Backup backups were running. (It was paging over 2000 pages per
second.)
>When I did a Q ALLOC PAGE, it indicated the percentage used was 55%.
>
>Presently (the backups have completed):
>ind
>AVGPROC-015% 01
>MDC READS-000142/SEC WRITES-000003/SEC HIT RATIO-093%
>STORAGE-000% PAGING-0001/SEC STEAL-000%
>Q0-00001(00000) DORMANT-00077
>Q1-00001(00000) E1-00000(00000)
>Q2-00000(00000) EXPAN-001 E2-00000(00000)
>Q3-00000(00000) EXPAN-001 E3-00000(00000)
>PROC 0000-015%
>LIMITED-00000
>Ready; T=0.01/0.01 07:42:42
>
>q alloc page
> EXTENT EXTENT TOTAL PAGES HIGH %
>VOLID RDEV START END PAGES IN USE PAGE USED
>------ ---- ---------- ---------- ------ ------ ------ ----
>510PAG F005 1 3338 600840 334304 443511 55%
> ------ ------ ----
>SUMMARY 600840 334304 55%
>USABLE 600840 334304 55%
>Ready; T=0.01/0.01 07:43:04
>
>Being the system utilization is still low, I am a bit apprehensive as to
>what will occur when the system gets busy through the day... Shouldn't the
>Q ALLOC PAGE percentage used have dropped?
>
>Thank you.
>
>Cecelia Dusha
Jim Bohnsack
Cornell Univ.
(607) 255-1760
