Solaris

Hi,

I am wondering if there is a way to free up memory in Solaris manually ? the way we can do it in Linux for example :

Code:

echo `/bin/date` "************* Memory Info Before *************"
free -m
sync
echo 1 > /proc/sys/vm/drop_caches
echo 2 > /proc/sys/vm/drop_caches
echo 3 > /proc/sys/vm/drop_caches
echo `/bin/date` "************* Memory Info After  *************"
free -m

Thanks.
Regards
Terry

First off you do not want to do that. It wrecks performance in spite of what you may think.

To deal with your question: Are you running zfs?

Edit - oops

http://www.solarisinternals.com/wiki...l_Tuning_Guide

You do not necessarily want to change zfs just because it appears that it is eating memory. It is supposed to look that way - have a read above.

Welcome to VM -- Once a host has been running a while, free ram pages of memory only occur in the window from when programs exit until other programs have not used up the freed pages, which were caching the heap and stack (swap backed pages). If you mmap() a file, and access the pages, they lay in ram until needed. You could exit, rerun, mmap() the same file, and read those same pages of ram. This works great for dynamic libraries, databases and all other sorts of stuff. All ram is a cache for disk.

Hi,

Thanks for your replies, appreciate it !!

I have two Solaris 11 VMs with Oracle Clusterware running on VBox, both of them with 4GiB RAM, problem is they get slower and slower and then all of a suden one of them gets crashed, it happens so frequently that I just cannot work, increasing RAM is out of question, previously I was running the same setup on Oracle Linux 5 and I was able to tweak the memory using the above script and never got a crash.

I need to find a way to tune the memory in solaris so the VMs can stay up and I can do the work.

Here are the mem stats from one of the server, this will give you an idea as to whats happening and you may be able to suggest me a way to tune them.

Just to let you know I am very new in Solaris so every bit of information will be very helpful to get this problem resolved.

echo ::memstat | mdb -k

Code:

Page Summary                Pages                MB  %Tot
------------     ----------------  ----------------  ----
Kernel                     202104               789   19%
ZFS File Data                9039                35    1%
Anon                       750232              2930   72%
Exec and libs               34059               133    3%
Page cache                  36889               144    4%
Free (cachelist)             6119                23    1%
Free (freelist)             10021                39    1%
Total                     1048463              4095

Please have a look at above stats and suggest me what to do.

Thank you very much for your assistance !

Regards
Terry

What work are you trying to do? What applications are you running? Are they Java-based?

you can also use #vmstat or #sdtprocess commands to monitor virtual memory. By this you can easily know which process you have to kill....

While in Linux the page caches can grow to 100%,
you see the page caches in Solaris are at 6%. No need for a drop_caches trick.
It looks like your Oracle DB consumes 2GB or more.
Take it down, and redo your memory measurement for comparison.