Page 5 of 6 FirstFirst ... 3456 LastLast
Results 41 to 50 of 53

Thread: HOWTO: Clear filesystem memory cache

  1. #41
    Join Date
    May 2010
    Location
    Tewkesbury uk
    Beans
    7,667
    Distro
    Ubuntu Development Release

    Re: HOWTO: Clear filesystem memory cache

    Hi

    Quote Originally Posted by tg3793 View Post
    To be more specific, programs stop responding, and the GUI freezes up from time to time. I know that the problem is tied to firefox; perhaps a plugin. However if I disable all of the plugins and restart firefox, I don't get 'all' of my memory back.

    In other words, if I start off at 30% of Ram and it creeps up to 80% after a few hours, if I disable all plugins (other than google talk) and restart firefox I might now be at 55%.

    I finally made it down to PCExpress and just bought a couple more Gigs of DDR2 800 RAM. We'll see what happens in a few hours. I started out at 20% about two hours ago and now I'm at 28%. Now 'that's' nothing to be concerned about.

    I'll keep watching it though. Maybe 10.04 just doesn't like hanging out with less than 4Gigs of RAM
    Maybe you have a memory leak.

    That would be a different issue than the issue highlighted by psusi. I like my caches flaming hot. I would prefer my memory refresh cycles to refresh data that i might need as opposed to refreshing it for data that i definitely won't need as it's not there.

    I have 3GB ram on my laptop and 10.04 flies along.

    Kind regards
    Join us on irc at #ubuntuforums. For web chat see here

    If you believe everything you read, you better not read. ~ Japanese Proverb

    Do not read newspapers on an empty stomach ~ Russian Proverb ~ BrunoLotse

  2. #42
    psusi is offline Ubuntu addict and loving it
    Join Date
    Sep 2005
    Location
    Orlando, FL
    Beans
    3,980
    Distro
    Ubuntu Development Release

    Re: HOWTO: Clear filesystem memory cache

    Quote Originally Posted by tg3793 View Post
    In other words, if I start off at 30% of Ram and it creeps up to 80% after a few hours, if I disable all plugins (other than google talk) and restart firefox I might now be at 55%.
    As measured how? If you are counting the cache in that figure, then that is perfectly normal.

  3. #43
    Join Date
    Aug 2010
    Location
    Philippines
    Beans
    143
    Distro
    Ubuntu 12.04 Precise Pangolin

    Re: HOWTO: Clear filesystem memory cache

    Quote Originally Posted by psusi View Post
    As measured how? If you are counting the cache in that figure, then that is perfectly normal.
    I wouldn't disagree that it "creeping up" to 80% or more isn't normal. But it's the not being able to flush it in any way shape or form (other than a reboot) that I wouldn't consider normal.

    And, as I had mentioned before, I'm measuring the memory usage with "free -m".
    ~ It has recently been discovered that research causes cancer in rats. ~

    BTW; I'm using Linux Mint (based on Precise) with MATE so modify Q/A accordingly if applicable.

  4. #44
    Join Date
    Aug 2010
    Location
    Philippines
    Beans
    143
    Distro
    Ubuntu 12.04 Precise Pangolin

    Re: HOWTO: Clear filesystem memory cache

    I mostly continuing this thread out of a curiosity to learn at this point. Ever since I added an extra 2Gig memory module I haven't had a problem Nice snappy system with several hours of use going from 20% usage to 53% usage.

    Still a problem that I can't "flush the memory" to get back down to the pre-boot 20% usage. But since the system continues to be nice and snappy I have no really need to now :-)

    This latest development seems to validate my general statement of "when it works it works, and when it doesn't it doesn't" ... Ok, well that's not very scientific so I'll "frame" it another way. It seems that there is a memory leak in firefox (most likely one of the plugins) that gradually eats up memory even when pushing the upper limit as hight as 95% to 98% memory usage. And when it starts to get that high the system really starts to choke.

    I'm using Ubuntu 10.04 and I understand that the memory management 'should' prevent this by pushing some of this to SWAP (how much or when I haven't researched yet).

    Now that I've added 2Gig of RAM (total of 4Gig now) I am still having the memory leak issue but the speed of the memory leak has remained stable. This has allowed me to continue operating at a nice snappy speed even at eighteen hours of operation. I'll continue monitoring usage and see if the memory leak grows at this steady rate thereby eating all of the four gig (just taking longer to do so).

    Again I don't know if it will eat the additional memory, I'm simply going to continue watching it. I'll report back here later for the edification of anyone interested :-)
    Last edited by tg3793; May 9th, 2011 at 08:59 AM. Reason: Provide More details.
    ~ It has recently been discovered that research causes cancer in rats. ~

    BTW; I'm using Linux Mint (based on Precise) with MATE so modify Q/A accordingly if applicable.

  5. #45
    Join Date
    May 2010
    Location
    Tewkesbury uk
    Beans
    7,667
    Distro
    Ubuntu Development Release

    Re: HOWTO: Clear filesystem memory cache

    Hi

    @tg3793

    This is old but the general principles still apply.

    http://tldp.org/LDP/tlk/mm/memory.html

    BTW: It just works on my machine. Have a look at the kernel source if you want to know how memory management is handled now.

    Kind regards
    Join us on irc at #ubuntuforums. For web chat see here

    If you believe everything you read, you better not read. ~ Japanese Proverb

    Do not read newspapers on an empty stomach ~ Russian Proverb ~ BrunoLotse

  6. #46
    Join Date
    Aug 2010
    Location
    Philippines
    Beans
    143
    Distro
    Ubuntu 12.04 Precise Pangolin

    Re: HOWTO: Clear filesystem memory cache

    Quote Originally Posted by matt_symes View Post
    This is old but the general principles still apply.
    http://tldp.org/LDP/tlk/mm/memory.html
    Thanks; good information.

    Quote Originally Posted by matt_symes View Post
    BTW: It just works on my machine.
    :-)
    ~ It has recently been discovered that research causes cancer in rats. ~

    BTW; I'm using Linux Mint (based on Precise) with MATE so modify Q/A accordingly if applicable.

  7. #47
    psusi is offline Ubuntu addict and loving it
    Join Date
    Sep 2005
    Location
    Orlando, FL
    Beans
    3,980
    Distro
    Ubuntu Development Release

    Re: HOWTO: Clear filesystem memory cache

    Quote Originally Posted by tg3793 View Post
    I wouldn't disagree that it "creeping up" to 80% or more isn't normal. But it's the not being able to flush it in any way shape or form (other than a reboot) that I wouldn't consider normal.

    And, as I had mentioned before, I'm measuring the memory usage with "free -m".
    But which column? The +/- cache or not? If it is not the +/- cache, then you can clear it as this thread describes, but shouldn't because that "used memory" is doing good. If it is the +/- cache line, then check the system monitor or top to see what program is hogging it all and kill it.

    total used free shared buffers cached
    Mem: 3939 3537 402 0 60 2035
    -/+ buffers/cache: 1441 2497

    The 3537 might look like a lot, but since 2035 of it is cache, there is not a problem. It is the 1441/2497 numbers you want to look at.

  8. #48
    Join Date
    Oct 2011
    Beans
    47

    Re: HOWTO: Clear filesystem memory cache

    My NAS server was running very slow and slow transfer speeds over the network was getting 30 - 40 MB/s when i usually get 90+ MB/s when I ssh into the machine it indicated 96.8 % mem usage out of 2GB RAM.

    I used the command by logging in as root.

    sudo su
    sync
    echo > 3 /proc/sys/vm/drop_caches

    now my system is working as normal and mem usage is back down to only 12%

    Thanks!

  9. #49
    Join Date
    Jun 2012
    Beans
    3

    Re: HOWTO: Clear filesystem memory cache

    Quote Originally Posted by crazy17 View Post
    Hi guys! This doesn't seem to work in 10.04. I get
    Code:
    bash: /proc/sys/vm/drop_caches: Permission denied
    I am not well versed in the terminal and have only been using linux for a couple of months now. I am using PAE with 6 gb of ram. Hope you guys can help. Oh, and the system monitor shows full memory cache use.
    use sudo command at first of the line ,

  10. #50
    Join Date
    Oct 2012
    Beans
    1

    Re: HOWTO: Clear filesystem memory cache

    hello my frinds ihave some problem Clearing cached memory on Linux system


    ineed script auto clean


Page 5 of 6 FirstFirst ... 3456 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •