Dũng Trần-Dương
2016-Aug-01 11:30 UTC
[CentOS-virt] Why does AWS instance always lost around 500MB memory
Hi,
I launched an AWS instance `t2.medium` (use CentOS 7 image
"ami-7abd0209",
product code: https://aws.amazon.com/marketplace/pp/B00O7WM7QW), which is
supposed to have 4GB Memory in total, but turn out it is only "3.5GB".
```
$ free -h
total used free shared buff/cache
available
Mem: 3.5G 441M 1.4G 16M 1.6G
2.7G
Swap: 0B 0B 0B
```
It does not happen to AWS Ubuntu 16.04.
```
$ free -h
total used free shared buff/cache
available
Mem: 3.9G 49M 3.3G 5.5M 518M
3.7G
Swap: 0B 0B 0B
```
This seems to happen to all AWS CentOS image, regardless which instance
type it is.
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Stephen John Smoogen
2016-Aug-01 13:29 UTC
[CentOS-virt] Why does AWS instance always lost around 500MB memory
On 1 August 2016 at 07:30, D?ng Tr?n-D??ng <chris.duong83 at gmail.com> wrote:> Hi, > > I launched an AWS instance `t2.medium` (use CentOS 7 image "ami-7abd0209", > product code: https://aws.amazon.com/marketplace/pp/B00O7WM7QW), which is > supposed to have 4GB Memory in total, but turn out it is only "3.5GB". >A rough guess would be that the system has reserved some memory for crashkernel but that is a guess. I would look at /proc/commandline to see what the kernel is starting up with. -- Stephen J Smoogen.
Dũng Trần-Dương
2016-Aug-02 06:57 UTC
[CentOS-virt] Why does AWS instance always lost around 500MB memory
Hi Stephen, I've just tested in Virtualbox, same thing happened to CentOS but the loss is lesser than in AWS. Both machines are allocated with 4096MB in Vagrantfile. ``` [vagrant at my-multi-centos-72 ~]$ cat /proc/meminfo MemTotal: 3882384 kB MemFree: 3527648 kB vagrant at my-multi-ubuntu-1604:~$ cat /proc/meminfo MemTotal: 4046708 kB MemFree: 3695204 kB ``` On Mon, Aug 1, 2016 at 8:29 PM Stephen John Smoogen <smooge at gmail.com> wrote:> On 1 August 2016 at 07:30, D?ng Tr?n-D??ng <chris.duong83 at gmail.com> > wrote: > > Hi, > > > > I launched an AWS instance `t2.medium` (use CentOS 7 image > "ami-7abd0209", > > product code: https://aws.amazon.com/marketplace/pp/B00O7WM7QW), which > is > > supposed to have 4GB Memory in total, but turn out it is only "3.5GB". > > > > A rough guess would be that the system has reserved some memory for > crashkernel but that is a guess. I would look at /proc/commandline to > see what the kernel is starting up with. > > > -- > Stephen J Smoogen. > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > https://lists.centos.org/mailman/listinfo/centos-virt >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20160802/a8bc7c8d/attachment-0002.html>