[ovirt-users] Memory and swap issue

[Itamar Heim]

On 06/05/2014 10:30 PM, Jeff Clay wrote:
> 126455 MB total, 863 MB used, 125592 MB free
>   That's what I'm showing right now, but I don't have as many VM's
> running at the moment. There are currently 8 running and I was getting
> that issue yesterday when I got around the 15 vm mark.
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> On Thu, Jun 5, 2014 at 2:07 PM, Itamar Heim <iheim at redhat.com
> <mailto:iheim at redhat.com>> wrote:
>
>     On 06/05/2014 02:24 AM, Jeff Clay wrote:
>
>         I'm getting the following error trying to start a VM. I have 64
>         gb of
>         RAM on this host. I got this error once before and found that my
>         swap
>         partition was only 2gb or so. I increased the swap size to 124GB
>         and the
>         problem went away. Below is the error when trying to start a VM and
>         below that is what my output from "free -g". I don't see why I'm
>         getting
>         a swap file error when there's plenty of it available.
>
>
>            * Cannot run VM. Host swap percentage is above the defined
>         threshold.
>
>              - Check your configuration parameters for Host Swap Percentage.
>            * Cannot run VM. There is no host that satisfies current
>         scheduling
>
>              constraints. See below for details:
>            * The host USARPAOVRTHOST02 did not satisfy internal filter
>         Memory.
>
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>
>         [root at usarpaovrthost02 ~]# free -g
>                        total       used       free     shared    buffers
>              cached
>         Mem:            62         62          0          0          0
>                12
>         -/+ buffers/cache:         50         12
>         Swap:          123         12        110
>         [root at usarpaovrthost02 ~]#
>         [root at usarpaovrthost02 ~]#
>         [root at usarpaovrthost02 ~]# swapon -s
>         Filename                                Type            Size    Used
>         Priority
>         /dev/dm-1                               partition       129490936
>         12811000        -1
>         [root at usarpaovrthost02 ~]#
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>
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>
>
>     what do you see under host general subtab for swap percentage?
>
>

iirc, you can either disable the swap check via the config 
EnableSwapCheck, or change the threshold via 
BlockMigrationOnSwapUsagePercentage
(which would be a confusing name if it affects RunVm and not only 
migration...)