Topic
6 replies Latest Post - ‏2013-01-23T05:53:16Z by SystemAdmin
Osama Munir
Osama Munir
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Pinned topic How do I clear RHEL3 Cache get allocation to RAM

‏2010-03-24T09:58:37Z |
Hi

I am running in Issue that my total system RAM is 8GB. If I run command

free -m I get 6.0 Gb RAM
free -m
total used free shared buffers cached
Mem: 7554 5928 1626 0 123 4798
-/+ buffers 1006 6548
Swap: 1996 0 1996

Where as TOP command shows only procesess using 10% of RAM that is 1 GB. Now I read different blogs and understood that cache is also available RAM.

Then I tried to remove cache by ../cache_drops but RHEL3 dont support this command.

Keeping this in mind I allocated 4GB more to Apache Tomcat. Then I started but Tomcat failed to get this much memory. Although this should be free RAM.

I want to know how I can get rid of this CACHE and get memory to RAM.

Br
Osama
Updated on 2013-01-23T05:53:16Z at 2013-01-23T05:53:16Z by SystemAdmin
  • ishields
    ishields
    988 Posts
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    Re: How do I clear RHEL3 Cache get allocation to RAM

    ‏2010-03-24T11:47:39Z  in response to Osama Munir
    I'm not sure I understand what problem you are trying to solve. It seems your system is only using a small part of RAM for actual work, so a lot if available for caching which should help performance of what is running. RHEL3 is now quite old and its support lifecycle (see Red Hat Enterprise Linux Life Cycle) ends in October 2010 (a little over six months from now),

    If you are still concerned, you may be able to find more information from the slabtop or vmstat commands.

    Ian Shields
    • M36C_Balasubramanian_Rathinaku
      1 Post
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      Re: How do I clear RHEL3 Cache get allocation to RAM

      ‏2012-05-15T12:45:30Z  in response to ishields
      Hi

      User the following command in redhat to clear the cache safely.

      sync; echo 3 > /proc/sys/vm/drop_caches
      Regards

      B. Rathinakumar

      rathinakumarb@gmail.com
      NSN
      • SystemAdmin
        SystemAdmin
        2364 Posts
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        Re: How do I clear RHEL3 Cache get allocation to RAM

        ‏2012-09-06T06:47:44Z  in response to M36C_Balasubramanian_Rathinaku
        Hi,

        I hope below can be helpful.

        Ensure that, you logged in with root user

        1. free -tom

        1. dd if=/dev/zero of=/root/cache1 bs=1024M count=2
        2. dd if=/dev/zero of=/root/cache2 bs=1024M count=2

        1. rm -rf /root/cache1 /root/cache1

        1. free -tom

        Cheers,
        Anil
        anilkumar.pinnaka@gmail.com/ anilkumar.pinnaka@yahoo.com
  • SystemAdmin
    SystemAdmin
    2364 Posts
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    Re: How do I clear RHEL3 Cache get allocation to RAM

    ‏2012-11-04T03:53:13Z  in response to Osama Munir
    I've also wanted to check this out on the web.
    There seems to be no relevant solution.
    On the other hand, some guy on www.prodaft.com advised to use "echo 3 > /proc/sys/vm/drop_caches"
    • SystemAdmin
      SystemAdmin
      2364 Posts
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      Re: How do I clear RHEL3 Cache get allocation to RAM

      ‏2012-11-04T04:19:30Z  in response to SystemAdmin
      By the way the subjected site "was" (not "is" http://www.prodaft.com.).
      I wanted to post the link as reference but looks like a totally different site atm.

      Hope you can find more resources on the web.
  • SystemAdmin
    SystemAdmin
    2364 Posts
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    Re: How do I clear RHEL3 Cache get allocation to RAM

    ‏2013-01-23T05:53:16Z  in response to Osama Munir
    If you are not having memory you can go for external hard disk also.
    online tech support and remote services for emergency repair and maintenance.