Fedora 4 memory troubles

Discussion in 'Installation/Configuration' started by spazmo360, Dec 14, 2005.

  1. spazmo360

    spazmo360 New Member

    Hello, I am having a lot of problems with a recent FC4 installation.

    Basically - the system was really starting to crunch with not much happening. (I have had a lot more stuff running on RH9 with the same spec hardware)

    I am running on Intel P3 2Ghz with Geforce2 32MB and 256MB PC2700.

    I had a look at the system monitor and ram is constantly creeping up - til the point where there is nothing left.
    Then I noticed that it shows that 0MB of swap is being used.

    I ran 'free' in a terminal and it showed that there was 0 swap also. as in :
                 total       used       free     shared    buffers     cached
    Mem:      255636     251724       3912          0       1760      58988
    -/+ buffers/cache:     190976      64660
    Swap:        0          0          0
    kernel is 2.6.11-1.1369_FC4

    Then I also noticed that fstab had no reference to SWAP - so I created one and rebooted - but 'free' and sytem monitor still show that 0 swap is being used / exists.

    Is this normal - and if so how does FC4 handle memory and is there any way to fix these memory woes - or is it time to move away from Redhat - frankly I need a stable system (like RH9) and I am starting to resent being forced into being a constant beta tester for RHES if I want to use Fedora.

    Thanks in advance for any clues or help with this.
  2. till

    till Super Moderator Staff Member ISPConfig Developer

    Generally all current linux distributions like fedora are caching opened files in RAM. Its normal that you do naot have free RAM, the kernel uses all free RAM to cache files until the space is needed for running programs.
  3. spazmo360

    spazmo360 New Member

    Thanks for the reply.

    That's fine.

    Why when all physical ram is used doesn't it use the swap or even acknowledge a swap - why have a swap at all then ?

    What I'm trying to understand is why the performance sucks compared to RH9 or even FC3

    I have less processes running than on RH9 and the macine becomes unresponsive very quickly - the nearest I can get to is the complete lack of acknowledgement of the swap - but if I'm wrong then is there any other reason anyone is aware of that would cause this ? CPU usage is virtually 0% .
    Last edited: Dec 14, 2005
  4. falko

    falko Super Moderator Howtoforge Staff

    Did you have a look at the log files in /var/log to find out what could cause this behaviour?
  5. spazmo360

    spazmo360 New Member

    OK I'm checking thru /var/lod/messages/ - anything in partiular I should be trying to grep ?

                 total       used       free     shared    buffers     cached 
    Mem:        256136     254760       1376          0       1260      58312 
    -/+ buffers/cache:     195188      60948 
    Swap:       524280      54500     469780 
    My mate just sent me this off his FC3 - he has a swap thats being used -
    I'm fairly sure this is where my problem is - so how do enable swap in FC4 - everywhere I look I keep getting answers like "FC4 uses all physical ram until other processes need it" -

    Well other processes need it !

    CAn someone please c'n'paste the output from 'free' on their FC4 installation - thanks.
    Last edited: Dec 14, 2005
  6. spazmo360

    spazmo360 New Member

    OK - I've fixed the missing SWAP.

    1. edit fstab and specify swap by device instead of LABEL ---- i.e

    /dev/hda3 swap swap defaults 0 0

    instead of

    LABEL=SWAP-hda3 swap swap defaults 0 0

    2. then just type swapon -a at command prompt.

    Bingo - here is the output of 'free' now:
                 total       used       free     shared    buffers     cached
    Mem:        255636     252260       3376          0        276      69324
    -/+ buffers/cache:     182660      72976
    Swap:      1052248       1240    1051008
    At the end of the day - ALL systems need a swap - or paging file as windows calls it - even if you have plenty of RAM.
    For some reason FC4 didn't initialise the swap - why ? I don't know but it sucks and I'm not the only person who has had this problem - I've seen this mentioned on a few mailing lists with responses from people saying that Fedora is so smart it doesn't need one !

    whether this sorts performance issues - I hope it will - in the meantime I think I'll continue with my 10th attempt at getting up2date to work (now thats a whole other nightmare and thread)

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