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SRX and low available memory

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  • 1.  SRX and low available memory

    Posted 06-01-2012 12:47

    We use some time (more than one year) SRX240. Since last upgrade without upgrade. In the last time we get alarms "low available memory, lower than threshold" ... when I type "show system process brief" I get there 27MB RAM free only.


    As i observe there is no swap configured. When will be memory exhausted, we need to reboot both boxes of cluster?


    Has someone such experience? Or srx use all memory and no crash, low memory deadlock etc, is happen?


    Thanks for any comments


    Best regards


  • 2.  RE: SRX and low available memory

    Posted 06-03-2012 03:17


    It is generally recommanded to keep finite amount of meemory for box functioning correctly.

    You can best do is remove the unnecessary log files/back software copy(if available) it will free some space from the device.

    You can do via

    root#run request system storage cleanup<<<<<<<<<<<<<<<<To delete the unnecessary files.


    If there are memory full in SRX, box might misbehave in functionality.

  • 3.  RE: SRX and low available memory

    Posted 06-04-2012 01:43

    Hi deepakcr,

    thanks for your respnse.

    I have found souch description of FreeBSD ... (

    mbuf clusters

    FreeBSD stores the network data in the mbuf clusters 2Kb each, but only 1500B are used in each cluster (the size of the Ethernet packet)

    For each mbuf cluster there is “mbuf” structure needed, which have 256B in size and used to organize mbuf clusters in chains. There’s possibility to store some additional useful 100B data into the mbuf, but it is not always used.

    If server have the RAM of 1Gb or more 25 thousands of mbuf clusters will be created by default but it is not enough in some cases.

    When there’s no any free mbuf clusters available FreeBSD enters the zonelimit state and stops to answer to any network requests. You can see it as the `zoneli` state in the output of the `top` command.

    So I expect the behavior will be the same ... if will be all memory consumed.
    I am solving this with JTAC.


  • 4.  RE: SRX and low available memory

    Posted 06-06-2012 04:25

    Case is closed now, box should be ok ... by JTAC. When I check memory via "show system process brief" then I see 5-45MB RAM free ...

  • 5.  RE: SRX and low available memory
    Best Answer

    Posted 06-20-2012 02:12
    Everything seems ok now ... and used memory seems ok ... I have 52MB RAM free on active node and 75MB RAM free on backup node ... really seems all to be ok.

  • 6.  RE: SRX and low available memory

    Posted 02-07-2013 01:29

    Indeed. I have the same dillemma. Hopefully cleaning up and applying the principle shared by good guys here solves mine. Thanks men.

  • 7.  RE: SRX and low available memory

    Posted 02-07-2013 05:38

    What version of Junos are you running and are you utilizing UTM functionality such as AV and/or IDP?  If 11.4R5 introduced a new feature to help with control-plane memory usage which can be found here.

  • 8.  RE: SRX and low available memory

    Posted 05-17-2018 23:02

    Hi Guys


    I have one issue an interesting one, please support


    I have one EX 9208 switch shaving 16 GB of memory out of which only 1 GB isused and remaining 2 GB is showing n free memory and remamining memory in inactive memory around 12 GB, ideal process is memory should stayu in free memory but in my case it is showing in inact memory. can someone please help me out on it.?