Memory used by oracle

Alba florencia05 at gmail.com
Mon Aug 17 14:54:36 UTC 2009


All,

First of all, thanks for the link ESG. It is indeed pretty usefull.
Unfortunately I am running into some problems still. I did change the way I
was calculating my used memory as Yong pointed out (thanks also!). On the
server I included on the original email the new numbers ran ok after
updating the way of calculating the used memory. When I tried to do the same
thing on another server I ran into a situation where ipcs still shows shared
memory segments that in total are bigger than the used memory taken from the
free command.

[root at bcdserver ~]# free -m
             total       used       free     shared    buffers     cached
Mem:          8988       8936         52          0        215       5792
-/+ buffers/cache:       2927       6061
Swap:         3999        222       3777
[root at bcdserver ~]# ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
0x0a008784 0          root      666        4096       2
0x040087ac 32769      root      600        4096       0
0xb98eb8e8 65538      oracle    640        132120576  21
0x2fd85d4c 98307      oracle    660        1612709888 66
0x88c037f0 131076     oracle    660        4297064448 64
0x036ad664 163845     oracle    660        1033895936 38

If I got it right this time... the used memory on the server is 6231Mb
(8936-2927+222) and the shared memory segments are taking up to 6748 Mb...
and that is not including non-shared memory used by the oracle processes.

Last but not least... as for the top command... unfortunately top is only
showing me up to 40 proccesses and the server has 500+ oracle processes
running. I was not sure about using it cause I am leaving way to many
processes running outside the calculations. Still, here is the output for it
if it helps anyone to figure this out:

top - 09:42:58 up 22 days,  5:40,  1 user,  load average: 1.52, 1.49, 1.45
Tasks: 378 total,   3 running, 375 sleeping,   0 stopped,   0 zombie
Cpu(s): 23.6%us,  2.0%sy,  0.0%ni, 73.2%id,  1.0%wa,  0.1%hi,  0.2%si,
0.0%st
Mem:   9204696k total,  9136184k used,    68512k free,   215304k buffers
Swap:  4095992k total,   228120k used,  3867872k free,  5926108k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
14745 oracle    17   0 4518m 2.4g 2.1g R 89.2 27.3 992:41.43 oracle
17083 oracle    15   0 4246m 2.2g 2.2g S  0.0 25.1  27:21.22 oracle
20306 oracle    15   0 4256m 2.1g 2.1g S  0.0 23.8   5:14.00 oracle
20300 oracle    15   0 4274m 1.9g 1.8g S  0.0 21.4  20:39.20 oracle
20290 oracle    -2   0 4255m 1.9g 1.9g S  1.0 21.3 287:57.76 oracle
20294 oracle    -2   0 4255m 1.9g 1.9g S  1.0 21.3 274:22.52 oracle
20298 oracle    15   0 4241m 1.8g 1.7g S  0.0 19.9   2:32.48 oracle
 2858 oracle    15   0 4249m 1.7g 1.7g S  0.0 19.4   4:57.83 oracle
 6871 oracle    15   0 4249m 1.6g 1.6g S  0.0 18.5   7:58.53 oracle
23176 oracle    15   0 4249m 1.6g 1.6g S  0.0 18.4   4:28.51 oracle
 6798 oracle    15   0 4247m 1.6g 1.6g S  0.0 18.4   8:23.82 oracle
21075 oracle    15   0 4245m 1.6g 1.6g S  0.0 18.2   5:58.52 oracle
20325 oracle    15   0 4244m 1.6g 1.5g S  0.0 17.7   8:45.69 oracle
20310 oracle    15   0 4246m 1.5g 1.5g S  0.0 17.1  15:25.91 oracle
19200 oracle    15   0 4257m 1.5g 1.5g S  0.0 16.7   1:56.80 oracle
 9163 oracle    15   0 4253m 1.4g 1.3g S  0.0 15.5   2:21.30 oracle
11617 oracle    15   0 4249m 1.4g 1.4g S  0.0 15.5   2:49.91 oracle
 4249 oracle    15   0 1703m 1.3g 1.3g S  0.0 15.1   4:59.03 oracle
 4251 oracle    15   0 1697m 1.3g 1.3g S  0.0 15.1   5:45.87 oracle
11530 oracle    15   0 4247m 1.3g 1.3g S  0.0 14.8   2:49.50 oracle
 1902 oracle    15   0 4246m 1.3g 1.3g S  0.0 14.5   0:12.34 oracle
 7077 oracle    15   0 1691m 1.3g 1.2g S  0.0 14.3   7:03.08 oracle
17074 oracle    15   0 1686m 1.2g 1.2g S  0.0 13.7  57:06.54 oracle
19651 oracle    15   0 1688m 1.2g 1.2g S  0.0 13.3   1:14.97 oracle
12764 oracle    15   0 4248m 1.2g 1.2g S  0.0 13.2   1:09.54 oracle

Any insight on this would be greatly appreciated.

Regards,

Alba

On Mon, Aug 17, 2009 at 3:50 AM, ESGLinux <esggrupos at gmail.com> wrote:

> Hi,
> Sometime ago I asked something similar. (look in this list a thread with
> the
> subject  (something like sar for memory*) *
>
>
> *they suggested me to read this
>
> http://virtualthreads.blogspot.com/2006/02/understanding-memory-usage-on-linux.html
> *
>
> Although it didn´t resolve my doubt, it was very usefull for me to
> understand the complex of knowing the real used memory for a process,
>
> take a look at it,
>
> HTH
>
> Greetings
>
> ESG
>
>
> 2009/8/17 Kory V. Wheatley <kory.wheatley at gdev.isu.edu>
>
> > What does "top" show?  Would "free" command be more accurate?
> >
> > Yong Huang wrote:
> >
> >> [root at abcserver ~]# free -m
> >>>             total       used       free     shared    buffers
> cached
> >>> Mem:          8988       8906         82          0        102
> 5411
> >>> -/+ buffers/cache:       3392       5596
> >>> Swap:         3999       1577       2422
> >>>
> >>>
> >> ...
> >>
> >>
> >>> ... from the free
> >>> command I get that the system is using around 5Gb (Mem used - Mem
> cached
> >>> +
> >>> swap used). What am I doing wrong in here?
> >>>
> >>>
> >>
> >> 8906-3392+1577 = 7091 MB. Where did you get 5GB?
> >>
> >> Yong Huang
> >>
> >>
> >>
> >>
> >>
> >
> > --
> > redhat-list mailing list
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> > https://www.redhat.com/mailman/listinfo/redhat-list
> >
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