Re: lsps shows high values but system appears to be fine

On Apr 23, 10:52 pm, Hajo Ehlers <serv...@xxxxxxxxxxxxx> wrote:
On Apr 23, 5:28 pm, "steven_nospam at Yahoo! Canada"



<steven_nos...@xxxxxxxx> wrote:
I have several systems that run AIX 5L and Informix databases on them.
Most of these systems show values I would expect on a system. However,
one seems to give me some weird values in the lsps command.

Here are the details:

System Model: IBM,9131-52A
Number Of Processors: 4
Processor Clock Speed: 1648 MHz
CPU Type: 64-bit
Kernel Type: 64-bit
Memory Size: 7936 MB
Good Memory Size: 7936 MB

Informix Version 9.40 FC7

# oslevel -s
5200-10-00-0000

# lsps -a
Page Space Physical Volume Volume Group Size %Used Active
Auto Type
paging00 hdisk3 datavg 6400MB 37 yes
yes lv
hd6 hdisk5 rootvg 6656MB 100 yes
yes lv

# lsps -s
Total Paging Space Percent Used
13056MB 69%

# vmstat 10 10
System Configuration: lcpu=4 mem=7936MB
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
1 1 2715508 79451 0 10 10 335 776 0 786 16640 5220 7 2 90
2
1 0 2715519 79440 0 0 0 0 0 0 601 11137 3835 7 1 92
0
1 0 2715520 79411 0 0 0 0 0 0 641 34843 12786 24 2 74
0
1 0 2715529 79401 0 0 0 0 0 0 606 4249 1631 2 0 97 0
1 0 2715673 79242 0 0 0 0 0 0 648 17652 6941 11 1 88
0
1 0 2716015 78898 0 0 0 0 0 0 643 17268 6116 11 1 88
0
2 0 2716193 78742 0 0 0 0 0 0 697 22620 8057 14 1 85
0
2 0 2717113 77816 0 0 0 0 0 0 809 25793 9227 16 1 83
0
5 0 2716951 77872 0 1 0 0 0 0 777 26851 4535 12 3 84
0
0 0 2716921 77902 0 0 0 0 0 0 593 4828 1846 3 0 97 0

# vmstat -v
2031616 memory pages
1952077 lruable pages
73804 free pages
1 memory pools
333094 pinned pages
80.1 maxpin percentage
20.0 minperm percentage
80.0 maxperm percentage
57.1 numperm percentage
1114800 file pages
0.0 compressed percentage
0 compressed pages
57.7 numclient percentage
80.0 maxclient percentage
1127373 client pages
0 remote pageouts scheduled
5943302 pending disk I/Os blocked with no pbuf
25321 paging space I/Os blocked with no psbuf
2740 filesystem I/Os blocked with no fsbuf
0 client filesystem I/Os blocked with no fsbuf
1436111 external pager filesystem I/Os blocked with no
fsbuf

# lsattr -El aio0
autoconfig available STATE to be configured at system restart True
fastpath enable State of fast path True
kprocprio 39 Server PRIORITY True
maxreqs 4096 Maximum number of REQUESTS True
maxservers 50 MAXIMUM number of servers per cpu True
minservers 10 MINIMUM number of servers True

The Informix databases are operating on raw LVs and so there should
not be a double-caching issue that I have heard mentioned. I have
other databases on other servers with less memory and those do not
seem to be causing high paging activity.

The users are not complaining about slow performance or any noticeable
issues, so just wondering if anyone may have a suggestion as to
whether this is a problem, and if there are any settings I should be
looking at that could tell me why this system has decided to use a
significant portion of its paging space for no apparent reason.

Thanks in advance.

Steve

1)
Fromhttp://www.ibm.com/developerworks/views/aix/libraryview.jsp?search_by...

Part 3

Paging allocation type:
- deferred page space allocation
- late page space allocation
- early page space allocation.

The default policy of AIX is deferred page space allocation.

2)
For some reason your system is using pretty much file cache. Could be
NFS, log files and what the heck i know but it looks like the
computational pages get page out. So check for busy filesystem.

In case the paging rate is low the system is working as designed ;-)

hth
Hajo

A high % size of paging space in lsps could be partly due to the fact
that at various points of time comp pages have been paged out to
paging space. This is because about 57% of the memory is filled with
file pages which have been protected due to their high repage rates
and numperm being between minperm and maxperm.
Now unless paging space garbage collection is enabled, space in the
paging space is reserved (and shows up in lsps as used) even if the
page is brought to RAM again unless the process stops and releases
memory. (as per perf management guide)
Secondly, does having almost double the paging space (of the amount of
RAM) really helps?
Also what is the lru_file_repage parameter set to?

-Ashok Sangra
.

Relevant Pages

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