Signed-off-by: Patrick Lang <patrick.lang@hotmail.com>
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@@ -738,6 +738,41 @@ $ docker run -d --isolation default busybox top |
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$ docker run -d --isolation hyperv busybox top |
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``` |
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+### Specify hard limits on memory available to containers (-m, --memory) |
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+ |
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+These parameters always set an upper limit on the memory available to the container. On Linux, this |
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+is set on the cgroup and applications in a container can query it at `/sys/fs/cgroup/memory/memory.limit_in_bytes`. |
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+ |
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+On Windows, this will affect containers differently depending on what type of isolation is used. |
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+ |
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+- With `process` isolation, Windows will report the full memory of the host system, not the limit to applications running inside the container |
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+ ```powershell |
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+ docker run -it -m 2GB --isolation=process microsoft/nanoserver powershell Get-ComputerInfo *memory* |
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+ |
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+ CsTotalPhysicalMemory : 17064509440 |
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+ CsPhyicallyInstalledMemory : 16777216 |
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+ OsTotalVisibleMemorySize : 16664560 |
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+ OsFreePhysicalMemory : 14646720 |
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+ OsTotalVirtualMemorySize : 19154928 |
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+ OsFreeVirtualMemory : 17197440 |
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+ OsInUseVirtualMemory : 1957488 |
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+ OsMaxProcessMemorySize : 137438953344 |
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+ ``` |
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+- With `hyperv` isolation, Windows will create a utility VM that is big enough to hold the memory limit, plus the minimal OS needed to host the container. That size is reported as "Total Physical Memory." |
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+ ```powershell |
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+ docker run -it -m 2GB --isolation=hyperv microsoft/nanoserver powershell Get-ComputerInfo *memory* |
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+ |
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+ CsTotalPhysicalMemory : 2683355136 |
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+ CsPhyicallyInstalledMemory : |
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+ OsTotalVisibleMemorySize : 2620464 |
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+ OsFreePhysicalMemory : 2306552 |
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+ OsTotalVirtualMemorySize : 2620464 |
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+ OsFreeVirtualMemory : 2356692 |
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+ OsInUseVirtualMemory : 263772 |
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+ OsMaxProcessMemorySize : 137438953344 |
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+ ``` |
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+ |
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+ |
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### Configure namespaced kernel parameters (sysctls) at runtime |
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The `--sysctl` sets namespaced kernel parameters (sysctls) in the |