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Ok, I've a COS7 server that also acts as a VirtualBox host.

I've got two virtual machines running; a Windows 10 machine (no issues), and a COS7-based mail server.

Now, the Windows 10 VM doesn't appear to exhibit any problems, but the COS7 mail server seems to have a memory leak, that causes the swap partition (2G) to gradually fill until there's sod all free; the first symptom of which is that mail turns up 'unchecked' as ClamAV shuts down. Reboot the VM and everything works again. It would appear that swap isn't being released.

I've got other linux vms that I run on my Windows 10 laptop (admittedly not continuously), that don't seem to exhibit the same problem. Anyone got any ideas?
I appreciate that it could be a virtualbox issue, but as the other windows VM doesn't have the problem, my initial thought is COS.

I don't seem to see the same problem on real machines.

[Host]
COS : 7.8.1 / Memory : 32G / Processor FX8350
VirtualBox : 6.1.14

[Guest]
COS : 7.8.1 / Memory : 2G
Friday, October 09 2020, 03:52 PM
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    Saturday, October 10 2020, 05:14 AM - #Permalink
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    As well as the script Nick provided, do a google search using something like "linux finding source of memory leak" - you will get many really good hits, some using just the standard OS provided tools...
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  • Accepted Answer

    Friday, October 09 2020, 06:34 PM - #Permalink
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    You could try this script and take a few snapshots over time to compare.
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    Friday, October 09 2020, 05:04 PM - #Permalink
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    I had similar - but that improved by turning on the virtualization bits and adding a second processor. That makes it run faster (noticably).
    The problem doesn't seem to be cpu (although I'll monitor that), it's definitely non-release of swap .. with a 2G swap partition, it starts minimal usage, then ramps up to over 1.5G used and not released. Odd. ClamAV shuts down, but the swap still isn't released.
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    Friday, October 09 2020, 04:19 PM - #Permalink
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    I have a VM in VirtualBox that I play around with occasionally for testing. I dusted it off a few days ago and had serious responsiveness issues with it. I think the main culprit was ClamAV which headed up towards 100% on a CPU. I had to remove it to get it responsive but that took a while because of the responsiveness. I think you need something like "yum remove clamav*", but then you'll lose mail scanning. It would probably be better to throw more memory at it, if you can.
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