Jim
---
go to the following for full list of available
oracle book.
http://www.oracle.com/pls/db112/homepage
which links to the 11gr2 install guide
Db install guides
http://www.oracle.com/pls/db112/portal.portal_db?selec
ted=11&frame=
which links to the following section on memory
http://download.oracle.com/docs/cd/E11882_01/install.1
12/e17163/pre_install.htm#sthref62
------
2.2.1 Memory Requirements
The following are the memory requirements for
installing Oracle
Database 11g Release 2.
*
At least 4 GB of RAM
To determine the RAM size, enter the
following command:
# /usr/sbin/prtconf | grep "Memory size"
If the size of the RAM is less than the required
size, then you must
install more memory before continuing.
*
The following table describes the
relationship between installed
RAM and the configured swap space recommendation:
Note:
On Solaris, if you use non-swappable memory,
like ISM, then you
should deduct the memory allocated to this space
from the available
RAM before calculating swap space.
RAM Swap Space
Between 4 GB and 16 GB Equal to the size
of RAM
More than 16 GB 16 GB
On 10/29/2010 2:01 PM, Jim Mauro wrote:
Thanks Mike. Good point on the script.
Indeed, use of speculative tracing would be a
better
fit here. I'll see if I can get something together
and
send it out.
Thanks,
/jim
On Oct 29, 2010, at 4:45 PM, Mike Gerdts wrote:
On Fri, Oct 29, 2010 at 2:50 PM, Robin
Cotgrove<ro...@rjcnet.co.uk> wrote:
Sorry guys. Swap is not the issue. We've had this
confirmed by Oracle and I can clearly see there is
96GB of swap awailable on the system and ~50GB of
main memory.
By who at Oracle? Not everyone is equally
qualified. I would tend to
trust Jim Mauro (who co-wrote the books[1] on
Solaris internals,
performance,& dtrace) over most of the people you
will get to through
normal support channels.
1. http://www.amazon.com/Jim-Mauro/e/B001ILM8NC/
How do you know that available swap doesn't
momentarily drop? I've
run into plenty of instances where a system has
tens of gigabytes of
free memory but is woefully short on reservable
swap (virtual memory,
as Jim approximates). Usually "vmstat 1" is
helpful in observing
spikes, but as I said before this could miss very
short spikes. If
you've already done this to see that swap is
unlikely to be an issue,
knowing that would be useful to know. If you are
measuring the amount
of reservable swap with "swap -l", you are doing
it wrong.
I do agree that there can be other shortfalls that
can cause this.
This may call for speculative tracing of stacks
across the fork entry
and return calls, displaying results only when the
fork fails with
EAGAIN. Jim's second script is similar to what I
suggest, except that
it doesn't show the code path taken between
syscall::forksys:entry and
syscall::forksys:return.
Also, I would be a little careful running the
second script as is for
long periods of time if you have a lot of forksys
activity with unique
stacks. I think that as it is @ks may grow rather
large over time
because the successful forks are not cleared.
--
Mike Gerdts
http://mgerdts.blogspot.com/
_______________________________________________
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_______________________________________________
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dtrace-discuss@opensolaris.org
--
Oracle<http://www.oracle.com>
James Litchfield | Senior Consultant
Phone: +1 4082237059<tel:+1%204082237059> | Mobile:
+1 4082180790
<tel:+1%204082180790>
Oracle Oracle ACS
California
Green Oracle<http://www.oracle.com/commitment>
Oracle is committed to
developing practices and products that help protect
the environment
<div id="jive-html-wrapper-div">
This is what Oracle says about swap for 11gR2.
The comment about
subtracting ISM is not<br>
correct. A simple test shows that ISM does consume
swap (even if
it's not DISM). Think<br>
about what happens when a memory segment is created
(before it goes
to ISM), if someone<br>
happens to attach in non-ISM mode and when everyone
detaches from
the segment and it<br>
ceases to be ISM). In the first and last stage swap
space is
*required* and the VM system<br>
reserves the space needed when the segment is first
created.<br>
<br>
I would be cautious about Oracle assurances...<br>
<br>
Jim<br>
---<br>
<br>
<blockquote type="cite">go to the following for
full list of
available oracle book.<br>
<a moz-do-not-send="true"
class="moz-txt-link-freetext"
ref="http://www.oracle.com/pls/db112/homepage";>http://
www.oracle.com/pls/db112/homepage</a>
<br>
<br>
which links to the 11gr2 install guide<br>
Db install guides<br>
<a moz-do-not-send="true"
class="moz-txt-link-freetext"
ref="http://www.oracle.com/pls/db112/portal.portal_db?
selected=11&frame=">http://www.oracle.com/pls/db11
2/portal.portal_db?selected=11&frame=</a>
<br>
<br>
which links to the following section on memory
<br>
<a moz-do-not-send="true"
class="moz-txt-link-freetext"
ref="http://download.oracle.com/docs/cd/E11882_01/inst
all.112/e17163/pre_install.htm#sthref62">http://downlo
ad.oracle.com/docs/cd/E11882_01/install.112/e17163/pre
_install.htm#sthref62</a>
<br>
<br>
<br>
------<br>
2.2.1 Memory Requirements<br>
<br>
The following are the memory requirements for
installing Oracle
Database 11g Release 2.<br>
<br>
*<br>
<br>
At least 4 GB of
RAM<br>
<br>
To determine the RAM
size, enter the following command:<br>
<br>
# /usr/sbin/prtconf | grep "Memory size"<br>
<br>
If the size of the RAM is less than the required
size, then you
must install more memory before continuing.<br>
<br>
*<br>
<br>
The following
table describes the relationship between
installed RAM and the configured swap space
recommendation:<br>
<br>
Note:<br>
On Solaris, if
you use non-swappable memory, like ISM, then
you should deduct the memory allocated to this
space from the
available RAM before calculating swap space.
<br>
RAM Swap Space<br>
Between 4 GB and
16 GB Equal to the size of
RAM<br>
More than 16
GB 16 GB</blockquote>
<br>
<br>
<br>
On 10/29/2010 2:01 PM, Jim Mauro wrote:
<blockquote
ite="mid:45d35217-5bfa-40b3-9bb4-cbdc52813...@oracle.c
om"
type="cite">
<pre wrap="">Thanks Mike. Good point on the script.
Indeed, use of speculative tracing would be a better
fit here. I'll see if I can get something together
and
send it out.
Thanks,
/jim
On Oct 29, 2010, at 4:45 PM, Mike Gerdts wrote:
</pre>
<blockquote type="cite">
<pre wrap="">On Fri, Oct 29, 2010 at 2:50 PM, Robin
Cotgrove<a class="moz-txt-link-rfc2396E"
href="mailto:ro...@rjcnet.co.uk";><ro...@rjcnet.co.
k></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Sorry guys. Swap is not the issue.
We've had this confirmed by Oracle and I can clearly
see there is 96GB of swap awailable on the system
and ~50GB of main memory.
/pre>
</blockquote>
<pre wrap="">
By who at Oracle? Not everyone is equally qualified.
I would tend to
rust Jim Mauro (who co-wrote the books[1] on Solaris
internals,
performance,& dtrace) over most of the people
you will get to through
normal support channels.
1.<a class="moz-txt-link-freetext"
href="http://www.amazon.com/Jim-Mauro/e/B001ILM8NC/";>h
ttp://www.amazon.com/Jim-Mauro/e/B001ILM8NC/</a>
How do you know that available swap doesn't
momentarily drop? I've
run into plenty of instances where a system has tens
of gigabytes of
free memory but is woefully short on reservable swap
(virtual memory,
as Jim approximates). Usually "vmstat 1" is helpful
in observing
spikes, but as I said before this could miss very
short spikes. If
you've already done this to see that swap is unlikely
to be an issue,
knowing that would be useful to know. If you are
measuring the amount
of reservable swap with "swap -l", you are doing it
wrong.
I do agree that there can be other shortfalls that
can cause this.
This may call for speculative tracing of stacks
across the fork entry
and return calls, displaying results only when the
fork fails with
EAGAIN. Jim's second script is similar to what I
suggest, except that
it doesn't show the code path taken between
syscall::forksys:entry and
syscall::forksys:return.
Also, I would be a little careful running the second
script as is for
long periods of time if you have a lot of forksys
activity with unique
stacks. I think that as it is @ks may grow rather
large over time
because the successful forks are not cleared.
--
Mike Gerdts
<a class="moz-txt-link-freetext"
href="http://mgerdts.blogspot.com/";>http://mgerdts.blo
gspot.com/</a>
_______________________________________________
dtrace-discuss mailing list
<a class="moz-txt-link-abbreviated"
href="mailto:dtrace-discuss@opensolaris.org";>dtrace-di
sc...@opensolaris.org</a>
</pre>
</blockquote>
<pre wrap="">
_______________________________________________
dtrace-discuss mailing list
<a class="moz-txt-link-abbreviated"
href="mailto:dtrace-discuss@opensolaris.org";>dtrace-di
sc...@opensolaris.org</a>
</pre>
</blockquote>
<br>
<br>
<div class="moz-signature">-- <br>
<a href="http://www.oracle.com";
target="_blank"><img
src="cid:part1.03060504.05020101@oracle.com"
alt="Oracle"
border="0" height="26" width="114"></a><br>
nt size="2" color="#666666" face="Verdana, Arial,
Helvetica,
sans-serif">James Litchfield | Senior
Consultant<br>
Phone:<a href="tel:+1%204082237059">+1
4082237059</a> |
Mobile:<a href="tel:+1%204082180790">+1
4082180790</a> <br>
<font color="#ff0000">Oracle</font> Oracle
ACS<br>
California</font>
r>
<a href="http://www.oracle.com/commitment";
target="_blank"><img
src="cid:part2.07030704.04000406@oracle.com"
alt="Green
Oracle" align="abscenter" border="0"
height="28" width="44"></a>
<font size="1" color="#4b7d42" face="Verdana,
Arial, Helvetica,
sans-serif">Oracle is committed to developing
practices and
products that help protect the
environment</font>
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