<div dir="ltr">I am a little confused on why my CentOS box is using so much RAM.  I currently have a small test setup which only has <b>12GB</b> of ram total.<div><br>When I log into the administrative interface it tells me:</div><div><br></div><div><h3 style="box-sizing:border-box;font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;line-height:1.1;color:rgb(54,54,54);margin-top:7px;margin-bottom:10px;font-size:16px"><u>Memory</u></h3><div class="gmail-current-values" style="box-sizing:border-box;border-bottom:1px solid rgb(209,209,209);float:left;padding:0px 5px 10px 0px;width:513.656px"><h1 class="gmail-available-count gmail-pull-left" style="color:inherit;font-family:inherit;font-size:24px;box-sizing:border-box;margin:3px 0px;font-weight:300;line-height:1.1;padding-left:0px;padding-right:5px;float:left">4.3</h1><div class="gmail-available-text gmail-pull-left" style="color:rgb(51,51,51);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;line-height:14px;margin:2px 0px;padding:0px 5px;float:left"><div style="box-sizing:border-box">Available</div><div style="box-sizing:border-box">of 15.5 GiB </div></div><div style="color:rgb(54,54,54);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">Over commit: 39% (allocated 45%)<br><br>11.1 GB Used</div><div style="color:rgb(54,54,54);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div><div style="color:rgb(54,54,54);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">Currently I am only running 3 VMs with memory allocations as follows:</div><div style="color:rgb(54,54,54);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Defined Memory:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">1024 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Physical Memory Guaranteed:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">1024 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px"><br></span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Defined Memory:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">3072 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Physical Memory Guaranteed:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">3072 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px"><br></span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Defined Memory:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">2048 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">Physical Memory Guaranteed:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">2048 MB</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px"><b>Or 6144MB used by VM</b></span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px"><br></span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><span style="font-size:12px">If I SSH into my ovirt host, and run TOP and sort by memory, the top usage items are:</span></font></div><div style="box-sizing:border-box;clear:left;padding-top:5px"><font color="#363636" face="Open Sans, Helvetica, Arial, sans-serif"><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">31896 qemu      <b>21.5%</b> 727:21.44 qemu-kvm</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"> 6008 qemu        <b>14.6%</b> 190:33.70 qemu-kvm</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"> 3019 ovirt            <b>13.6%</b>  35:47.64 java</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"> 5800 qemu         <b>8.5%</b> 784:26.88 qemu-kvm</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"> 2565 ovirt            <b>3.9%</b>  62:58.00 java</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">Everything else is pretty small compared, but for the OVIRT/QEMU we roughly get<br></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><b>Total: 62% = 7.45GB<br><br></b></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">So I am a bit confused as to the Ram being reported to me by the system (15.5GGB, but the system only has 12GB), and assuming OVIRT is using around 7-8GB, does a bare minimal install of CentOS really need 4-5GB of Ram to run?</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">This is a bare minimal install of CentOS7 running only Webmin and oVirt.  I think there are several things I don&#39;t understand here, and I am quite new to oVirt and would like to learn, so please excuse my inexperience if this is a silly question!</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px">Thanks either way, I am really happy I ditched my ESXi box :D</div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><b><br></b></div><div style="font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><b><br></b></div></font></div></div><div style="color:rgb(54,54,54);font-family:&quot;Open Sans&quot;,Helvetica,Arial,sans-serif;font-size:12px;box-sizing:border-box;clear:left;padding-top:5px"><br></div></div></div></div>